Jesus Christ, Son of God: How the Doctrine of Jesus Christ Relates to the Doctrine of the Trinity

 Humanity has had a notion of the divine longer than we have had alphabets, longer than we have farmed, longer than we can really know. Who is God? Is there only one, or are there many? How can we identify God? What are God’s attributes, powers, or weird party tricks? These questions and more have inspired many people from many religious traditions for many years. Christians in particular have been struggling for two thousand years to understand God.¹ Theology is that attempt to study God, the attempt to know the unknowable. Thankfully, God has revealed certain things about God’s own self to humanity. Through the lenses of Scripture, Christian tradition, human reason, and the experience of the Christian community, we are able to make certain claims about God, each of which has implications for how we view God and all of God’s creation. The doctrine of the Holy Trinity is based, in large part, on Christology. The Second Person of the Trinity, Jesus Christ, offers us a glimpse of the divine—the most comprehensive revelation offered to humanity.

Many people begin their exploration of the connection between the Doctrine of God and the Doctrine of Jesus Christ by focusing on the Trinity and then moving to Christology. Here we will do the opposite and begin with Christology. We need to establish the connection between humanity and divinity in the person of Jesus Christ and briefly explore why Christ came to live among us. The Church has handed down to us certain beliefs about Jesus Christ enshrined in the words of the Nicene Creed and in what has come to be known as the Chalcedonian Definition, along with the writings of theologians from antiquity to the present. These beliefs include ideas such as the hypostatic union of human and divine natures in the person of Jesus Christ, the means whereby Christ put on humanity, and the subject and importance of Christ’s work. Moving then to the Doctrine of God, we can examine some of the claims humanity has made about the divine—including the fact that we worship a triune God. St. Catherine of Siena writes in The Dialogue that Jesus Christ bridges the gap between humanity and God, allowing us to come close to God.² Her insightful revelation gives us a wonderful place to begin.

We believe that Jesus Christ is the Son of God. Therefore, Jesus Christ is fully divine. The Scriptural record, which for our purposes is assumed to be a clear and accurate portrayal of Jesus Christ and a faithful witness to his words and actions, shows Jesus’ own claims about his divinity, along with the claims of the Scripture writers themselves. Jesus tells us that “The Father and I are one” (John 10:30) and “whoever has seen me has seen the Father” (John 14:9b). The prologue to the Gospel of John also bears witness: “In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things came into being through him, and without him not one thing came into being.” (John 1:1-3). These are but three instances from a rich Scriptural record of claims about Jesus’ divinity, the breadth of which is too great to exhaustively report here. Christian tradition also bears witness to Jesus’ divinity, and the ancient and medieval theologians in particular quoted Scripture profusely in building the arguments that became part of that tradition.

The fact that Jesus Christ is divine was vigorously argued by several key theologians in the first five centuries. Gnosticism claimed that matter was evil and spirit good, which leaves no room for Jesus to be divine.³ Irenaeus of Lyons took on Gnosticism and proved that Jesus was fully divine by showing that Jesus was the Son of God and that the Son was not only present with the Father at creation, but was active in it; he also shows that Jesus forgave sins, which is something only God can do.⁴ Arianism claimed that Jesus Christ was created rather than begotten, which meant that Jesus Christ was not fully divine.⁵ Athanasius of Alexandria took on Arianism, proving that the Son of God is co-eternal with the Father and that he was begotten, not made, and of one being with the Father.⁶ Taken together, these works, along with many others, satisfy the question about Jesus’ divinity and his status as the Son of God.

We believe that Jesus Christ is fully human. Not only was there ancient controversy over Jesus’ divinity, but arguments raged over his humanity, too. We note that Jesus’ divinity and humanity are held in tension, as we will explore in a moment. Whether or not the divine Jesus Christ was human was a major point of contention in the early years of Christianity. Some of the same theologians who proved Christ’s divinity were active in proving his humanity, including Irenaeus, Athanasius, and Cyril. Others include Justin Martyr, Hilary of Poitiers, Augustine of Hippo, John of Damascus, and many more. They based their arguments, in large part, on Jesus’ fleshly birth. Both Irenaeus and Cyril take pains to show that Jesus would not have been born of a woman had it not been necessary for him to take on human flesh and nature.⁷ Irenaeus also seems very interested in the fact that Jesus experienced hunger, writing: “For as at the beginning it was by means of food that [the enemy] persuaded man, although not suffering hunger, to transgress God’s commandments, so in the end he did not succeed in persuading him that was hungered to take that food which proceeded from God.”⁸

We believe that Jesus Christ has two natures, one human and one divine, which are in hypostatic union. This means that neither nature was subsumed by the other, but both natures were in harmony. As in the question over Christ’s divinity, much of the work to define the Church’s position on the union of Christ’s two natures was done by wrestling with the Scripture and as a response to heretical teaching. Thus, Nestorianism claimed that Jesus had two distinct and separate natures, which meant that Jesus was two people sharing one body.⁹ Cyril of Alexandria took on Nestorianism, proving that Jesus Christ had two natures that were united hypostatically.¹⁰ Miaphysitism claimed that Jesus Christ one nature that was blended between his human and divine natures, which meant that Jesus was partially human and partially divine.¹¹ Pope Leo the Great of Rome took on Miaphysitism, proving that Jesus’ two natures, while distinct, were united in one flesh.¹²

Nestorianism, as mentioned above, argued that Jesus had two distinct, separate natures. It arose, however, over a question of what to call the Blessed Virgin Mary. Nestorius was Archbishop of Constantinople from 428 to 431.¹³ He objected to the way the Virgin Mary was referred to as Θεοτόκος (Theotokos, “God-bearer” or “Mother of God”), and preferred the term Θεοδόχος (Theodochos, “God-receiver”).¹⁴ Nestorius would have accepted the term Χριστοτόκος (Christotokos, “Christ-bearer” or “Mother of Christ”) as well.¹⁵ Cyril of Alexandria argued that Nestorius’ position was tantamount to professing that there were two Christs, which would be heresy: “for the Scripture says not that the Logos united to himself the person of a human being but that he became flesh.”¹⁶ “‘For us and for our salvation,’ [Christ] united human reality hypostatically to himself.”¹⁷ Likewise, “his flesh tasted death,” not his divine nature, and thus “this is the sense in which we confess one Christ and Lord.”¹⁸

We believe that Jesus Christ came to dwell among us in order to complete important work. To hear certain strains of American Protestants tell it, Jesus Christ came to take the penalty being meted out by the Father for humanity’s sin. By taking the punishment, death, he was able to give eternal life in heaven to his followers.¹⁹ This atonement theory is called Penal Substitutionary Atonement, and it arose during the Protestant Reformation.²⁰ But Penal Substitutionary Atonement was not the original atonement theory, nor the most popular. Others include Christus Victor, best illustrated by Aslan’s sacrifice in C.S. Lewis’ magisterial work, The Lion, The Witch, and the Wardrobe. Christus Victor is a reinterpretation of the patristic idea of the Ransom Theory of Atonement, whereby Jesus ransomed us by exchanging his own life for the lives of humanity.²¹ Another one, posited by St. Anselm of Canterbury, is called the Satisfactionary Theory of Atonement, whereby humanity’s deep disobedience is made up for by Christ’s supererogatory obedience.²² The final one we will mention here is also of patristic origin, the Recapitulation Theory of Atonement.²³ Irenaeus explains recapitulation especially well; he argues that Jesus Christ came as the Second Adam to take on human nature, human temptation, and so on and thus heal human nature: “He has therefore, in his work of recapitulation, summed up all things, both waging war against our enemy, and crushing him who had at the beginning led us away captives in Adam, and trampled upon his head . . . .”²⁴

None of the atonement theories mentioned here are inherently wrong. Nor is any one inherently more correct than the others. It’s quite possible that more than one, or even all of them, share some element of truth. Though each of us has a favorite—the present author generally chooses Christus Victor or Recapitulation, if it matters—ultimately, each one probably introduces an important angle to the discussion. Each one had a Christian theologian or group of theologians who proposed it and argued it successfully enough to be adopted by a portion of the Church. Each one attempts to answer the question of why. Why did Jesus Christ take on human nature and come and dwell among us? More importantly, why did Jesus Christ accept death on the cross? And what did Jesus’ resurrection actually accomplish?

Leaving aside for the moment the cross and empty tomb, Jesus Christ came to us to show us how we should live and to give us a glimpse of God. Jesus is the fullest revelation of God. As it is written, “whoever has seen me has seen the Father” (John 14:9b), and “he is the image of the invisible God” (Colossians 1:15a). According to the Gospel writers, Christ is the suffering servant who redeems our suffering (Mark), the personification and perfection of Torah (Matthew), the perfect man and the greatest prophet (Luke), and the Son of God (John). Jesus Christ gave his followers clear directions on what it means to be a disciple (Matthew 25), summarized the entirety of the Law and Prophets (Mark 12:29-30), and proclaimed to us that we need to change our mindsets and thinking, because the Kingdom of God is at hand (Matthew 4:17).

Taking again the crucifixion and resurrection, we are presented with an even greater reason for coming to us. Whether we accept one of the mentioned atonement theories, one of the many that aren’t mentioned here, or some mixture of several, we can agree that the cross mattered. Jesus died a torturous death after suffering an inhumane beating, yet three days later arose from the grave. In his resurrection Christ defeated death and opened the door to eternal life to all who will follow him.

It is no accident that the above sounds like an evangelistic speech. Jesus’ entire mission was to bring good news—to be good news—to a broken, dying world. In whatever way Christian theologians might interpret Jesus’ life, death, and resurrection, some measure of good news is inherently included. Jesus matters. The eternally begotten Son of God took on humanity and lived among us to complete important work. In so doing, Jesus shows us our best picture of God. And it is to God: Father, Son, and Holy Spirit, to whom we now turn.

We believe that we can make some claims about God. As mentioned in the opening paragraphs, the doctrine of the Trinity is based on the doctrine of Jesus Christ. Jesus provides for us the clearest revelation of who God is. Yet we are not limited to Jesus Christ alone for revelation about God’s attributes, nature, powers, or party tricks. We have the Bible, we have Christian tradition, we have our own intellect and ability to reason, and we have Christian experience to guide us.

One of the basic claims Christians make about God, enshrined in the Apostles’ Creed, Nicene Creed, and Athanasian Creed, is that God is the omnipotent creator of everything, seen and unseen. Only God is uncreated, for God is eternal. Some people have mischievously asked if God can create a rock so big that he cannot move it, thinking that question can disprove God’s omnipotence or his creative ability. The question is ridiculous. Why would God deign to do such a thing? What does it accomplish? C.S. Lewis hits on this in his book, The Problem of Pain, writing that “meaningless combinations of words do not suddenly acquire meaning because we can prefix to them the two other words: ‘God can.’ It remains true that all things are possible with God: the intrinsic impossibilities are not things but non-entities.”²⁵

The important thing is that God can create a rock so big that you cannot move it, and yet through epochs of time, wind and water—also creations of God—can break it down and move it aside. Whether we accept the theory of evolution or some form of creationism as the origin of the earth and of humankind, we agree that God has been behind it since the very beginning. God creates and rules over creation. Associated with the claim that God is the creator is the question about whether or not God created from nothing or from something. Most Christians tend to believe that God started completely from scratch—a development of Christianity’s struggle with Gnosticism.²⁶ The main part of this claim is that we believe that God created the world and the people who live thereon. In fact, we believe that God created the world and humanity in love, for love, and by love, because God is love.²⁷ Our sin broke the world, but God’s creation is not finished and God is working to heal creation and return us to full relationship with God. God’s love for us is indescribable and unstoppable, for “through [Christ] God was pleased to reconcile to himself all things, whether on earth or in heaven, by making peace through the blood of his cross” (Colossians 1:20). God’s creating acts are not finished, nor is God satisfied to sit back and let creation run by itself. Exactly how much God interacts with creation is up to some debate; some Christians believe he’s active but still fairly “hands off,” others believe that God cares what color shirt we choose to wear each day, while most believe something between these two extremes.²⁸

Another claim Christians make about God is that God is impassible—God doesn’t suffer. Other Christians, especially since the end of the last century, have accepted the idea that God can suffer, and that God suffers on our behalf or alongside us. God is invested in us, after all, and wants to see us come into full relationship with God. We can find theological giants on both sides of the debate, and it is unlikely to be fully worked out this side of eternity.

These claims are but examples, and we do not have room to explore them all here. Humanity can make, and has made, many claims about God. Some make sense and some are senseless. The biggest claim, the one that captured the attention of dozens of ancient Christian theologians, involves the very nature of God: the claim that God is one God in three Persons.

We believe in the Holy Trinity: Father, Son, and Holy Spirit. The fact that we have left this claim for last in no way reflects on its importance. The reader will have noticed Trinitarian thinking throughout this paper, particularly in the claim that we believe that Jesus Christ is the Son of God. For Christ to be the Son of God, fully divine, means that God must be much more complex than a monad. And although we have left aside the question of Pneumatology until this moment, the Holy Spirit is an important factor in God’s revelation of God to humanity.

The Apostles’ and Nicene creeds both make a Trinitarian claim, one that was worked out over centuries. We see all three persons of the Trinity at work in the world throughout Scripture. We see all three persons of the Trinity at work in the world since. The Church’s fathers and mothers, wrestling with Scripture, tradition, reason, and experience, arguing over claims of heterodox thought, came to the conclusion that we worship one God in three Persons: Father, Son, and Holy Spirit. They are co-eternal, co-equal, and omnipotent. They are uncreated and are eternal. Each Person of the Trinity and the Trinity as a whole is worthy of our worship. And while we cannot explain how in the world this may be, we can believe that however God’s nature is expressed it is holy and beautiful beyond description.

The key to understanding the Trinity is Jesus Christ. We believe that Jesus Christ is the Son of God, fully divine, eternally begotten of the Father. We believe that Jesus Christ took on humanity, and that within him human and divine natures were in perfect harmony and perfect hypostatic union. We believe that Jesus Christ came and dwelt among us to do the important work of teaching us how to live and to redeem us from sin and death. We believe that God is the omnipotent creator of all that is, seen and unseen. We believe that God is active in the world. We argue over whether God suffers or not, and both claims have validity. We believe in one God: Father, Son, and Holy Spirit. And we believe that God loves us with an indescribable love which will reconcile us to God.

1Note here that the term “God” is used to refer to the Unity, not merely to the Father—a convention used throughout this paper.

2Catherine of Siena, The Dialogue, trans. Suzanne Noffke, (New York: Paulist Press, 1980), 59.

3Robert Louis Wilken, The First Thousand Years: A Global History of Christianity, (New Haven: Yale University Press, 2012), 44.

4Irenaeus, “Against Heresies,” in Ante-Nicene Fathers, vol. 1, ed. Alexander Roberts, James Donaldson, and A. Cleveland Cox, trans. Alexander Roberts and William Rambaut (Buffalo, NY: Christian Literature, 1885), revised and edited for New Advent by Kevin Knight, http://www.newadvent.org/fathers/0103420.htm, III.16.2 and III.22.10.

5Wilken, First Thousand Years, 89.

6Athanasius of Alexandria, “Orations Against the Arians, Book 1” in The Trinitarian Controversy, tr. and ed. by William G. Rusch, (Minneapolis: Fortress Press, 1980), 1.9, 1.11, 1.13, and 1.14.

7Cyril, “Second Letter,” 133; Irenaeus, “Against Heresies,” III.22.2 and III.22.10.

8Irenaeus, “Against Heresies,” V.21.2.

9Wilken, First Thousand Years, 195-196.

10Cyril of Alexandria, “Second Letter to Nestorius,” in The Christological Controversy, ed. and tr. by Richard A. Norris, Jr., (Minneapolis: Fortress Press, 1980), 132-133.

11Wilken, First Thousand Years, 206. “In Greek, physis means “nature,” and monos means “only” (only one nature); mia means one. So the proper term for non-Chalcedonians is miaphysites, though in past historical writing monophysites has been more widely used.”

12Leo of Rome, “Letter to Flavian, commonly called ‘the Tome,’” in Nicene and Post-Nicene Fathers, Second Series, vol. 12, ed. Philip Schaff and Henry Wace. (Buffalo, NY: Christian Literature Publishing Co., 1895, revised and edited for New Advent by Kevin Knight, (https://www.newadvent.org/fathers/3604028.htm), IV.

13Alister F. McGrath, Christian Theology: An Introduction, 25^th Anniversary Sixth Edition, (Hoboken: Wiley, 2016), 357.

14Richard A. Norris, Jr., “Introduction,” in The Christological Controversy, ed. and tr. by Richard A. Norris, Jr., (Minneapolis: Fortress Press, 1980), 26.

15McGrath, Christian Theology, 223; Joshua D. Allison, “St. Cyril’s Christology: Understanding the Hypostatic Union of Jesus Christ,” (term paper for Christian Heritage 1, Perkins School of Theology, 2021), 1.

16Cyril, “Second Letter,” 134.

17Cyril, “Second Letter,” 133.

18Cyril, “Second Letter,” 133.

19Often related to that pronouncement is the idea that those who choose to not accept (or who are predestined to not accept) will burn in the fires of hell, conscious and tormented, for an eternity—an idea called “eternal concious torment.” I mention it here simply because it provides the ghost pepper jelly to the Penal Substituionary Atonement’s peanut butter in certain Protestant denominations.

20Ben Pugh, Atonement Theories: A Way through the Maze, (Eugene, OR: Wipf and Stock Publishers, 2014), 63. Pugh notes that Charles Hodge named the theory in the mid-nineteenth century, though the idea is rooted in the Protestant Reformation and the writings of Calvin and Luther.

21Pugh, Atonement Theories, 1.

22Pugh, Atonement Theories, 55.

23Pugh, Atonement Theories, 26.

24Irenaeus, “Against Heresies,” V.21.1. This idea was also expressed by Gregory of Nazianzus (ca. 329–390), Archbishop of Constantinople in the fourth century: “For that which he has not assumed he has not healed; but that which is united to his Godhead is also saved.” Gregory of Nazianzus, “Epistle 101:To Cledonius the Priest Against Apollinarius” in Ante-Nicene Fathers, vol. 1, ed. Alexander Roberts, James Donaldson, and A. Cleveland Cox, trans. Alexander Roberts and William Rambaut (Buffalo, NY: Christian Literature, 1885), revised and edited for New Advent by Kevin Knight, https://www.newadvent.org/fathers/3103a.htm

25C.S. Lewis, The Problem of Pain, quoted in McGrath, Christian Theology, 187-188.

26McGrath, Christian Theology, 198.

27Daniel Erlander, Manna and Mercy for All, (Minneapolis: Augsburg Fortress, 2018), 1.

28The idea that God would not only care about your shirt color but would show you his daily selection was the very closely held belief of my childhood best friend’s parents and the members of their church. Anecdotes are not data, however, so we may pay exactly as much attention to the claim as is warranted.

St. Cyril's Christology: Understanding the Hypostatic Union of Jesus Christ

The texts of the New Testament talk of Jesus Christ in terms that show both his humanity and his divinity. Through the First Council of Nicaea (325), theologians also spoke of Jesus in human and divine terms. St. Irenaeus of Lyons, among many others, gave us a wonderful Christology based on his assertion that Christ is both human and divine, in opposition to the Gnostics and Marcionites of his day. After 325, St. Athanasius of Alexandria defended God’s Trinitarian nature, largely basing his work on his Christology. St. Cyril of Alexandria, likewise, defended the Marian title “Theotokos” (often translated as “Mother of God”) through his Christology. In doing so, he developed a “one-subject” Christology, rejecting Nestorius’ “two-subject” Christology. Cyril’s Christology is important because it defines how we are to speak of Jesus Christ, Son of God, who took on human flesh and nature and dwelt among us.

In developing his Christology, Irenaeus did not speculate on how Jesus Christ’s divine and human natures might work.1 The issue of how Jesus Christ could be fully human and fully divine finally came to a head in the mid-fifth century. Nestorius (ca. 386 – ca. 450) was Archbishop of Constantinople from 428 to 431. Soon after taking that office, he preached a sermon in which he professed his discomfort with the way Christians had begun referring to the Virgin Mary as Θεοτόκος (Theotokos, “God-bearer” or “Mother of God”). He preferred the term Θεοδόχος (Theodochos, “God-receiver”).2 Others have pointed out that Nestorius would have accepted the term Χριστοτόκος (Christotokos, “Christ-bearer” or “Mother of Christ”) as well.3 Nestorius argued that a human cannot give birth to God. Thus, Mary bore the human Jesus, who was a temple for the Logos.4 Nestorius argued this because he believed that when we say that Mary is the Mother of God, we deny the fullness of Jesus’ humanity and his divinity.

Like Irenaeus and many other theologians before him, Nestorius builds his case on a comparison between Christ and Adam, wherein Christ recapitulated Adam’s acts and failures and thus succeeded at them, healing humanity and releasing us from the curse of sin.5 However, his chief inquiry is whether God has a mother.6 He quotes several Scriptures that seem to bolster his case, including Jesus’ words from John 3:6 (“What is born of the flesh is flesh, and what is born of the Spirit is spirit”), arguing that the Word “stooped down to raise up what had collapsed, but he did not fall.”7 He has problems with the idea that Jesus’ divine nature died at the crucifixion. Can God die? Nestorius argues no, writing: “If God died when consigned to the grave, the Gospel saying ‘Why do you seek to kill me, a man, who have spoken truth to you?’ [John 8:40] is meaningless.”8 Yet, “Christ is not a mere man, O slanderer! No, he is at once God and man.”9

It is important to note that Nestorius does not deny either the humanity or the divinity of Christ, nor does he deny that Jesus Christ had two natures. Instead, he argued that Christ put on our nature “like a garment,” that the “third day burial belonged to the man, not the deity.”10 In other words, Christ was both human and divine, but the divine nature was not fully affected by the suffering and death of Jesus’ human body and nature. “That which was formed in the womb is not in itself God,” he wrote.11 He reiterated his position in his second letter to Cyril on the subject, writing that “everywhere in Holy Scripture, whenever mention is made of the saving dispensation of the Lord, what is conveyed to us is the birth and suffering of the Lord, what is conveyed to us is the birth and suffering not of the deity but of the humanity of Christ . . . .”12 In his letter, he continues to build his argument on Scripture and reason, arguing that Jesus’ humanity and divinity are held separate from one another. “The body therefore is the temple of the Son’s deity, and a temple united to it by complete and divine conjunction, so that the nature of the deity associates itself with the things belonging of the body, and the body is acknowledged to be noble and worthy of the wonders related in the Gospels.”13 The word “conjoined” evokes for us the image of “conjoined twins”—twins who share one or more body parts but who each have their own personality and mental capacity. One example from my childhood was the two-headed monster from the Sesame Street television program who shared a torso but whose minds—and therefore heads—frequently were at odds with each other. Nestorius’ use of the word “conjoined” thus has the potential to be problematic because it leads to a belief that Jesus was double-minded, potentially to the point of inner turmoil and conflict.

Cyril’s response to Nestorius was as careful as Nestorius’ original argument, spanning several homilies and letters as the two bishops argued the matter. Cyril argues for what theologians have come to refer to as the doctrine of the hypostatic union. Hypostatic union may be defined as: “(1) the act by which a divine nature and a human nature are united in one hypostasis, and (2) the state of unity that results from that act.”14 Whereas Nestorius argues that the Logos dwelt within one specific human who was a sort of temple for the Logos, Cyril argues that the Logos dwelt within Jesus and joined their natures together in a unique way, thereby taking on humanity in general rather than a specific person.

In Cyril’s second letter to Nestorius, Cyril takes the position that Jesus Christ had two natures that were closely connected:

We do not say that the Logos became flesh by having his nature changed, nor for that matter that he was transformed into a complete human being composed out of soul and body. On the contrary, we say that in an unspeakable and incomprehensible way, the Logos united to himself, in his hypostasis, flesh enlivened by a rational soul, and in this way became a human being and has been designated “Son of man.” He did not become a human being simply by an act of will or “good pleasure,” any more than he did so by merely taking on a person.15

Cyril then argues that Christ had a fleshly birth, even though the Logos needs no second birth.16 But “‘for us and for our salvation,’ [Christ] united human reality hypostatically to himself.”17 Likewise, “his flesh tasted death,” not his divine nature, and thus “this is the sense in which we confess one Christ and Lord.”18 Cyril then turns to Nestorius’ idea that the human Jesus was a temple for the divine Word. He points out that “we do not worship a human being in conjunction with the Logos, lest the appearance of a division creep in by reason of that phrase, ‘in conjunction with.’”19 According to Cyril, though we might be tempted to think of the hypostatic union that Cyril describes as “pointless or unseemly,” we might find ourselves asserting that there are two Sons, which is problematic because it endangers the close connection of Christ’s two natures that Cyril has been arguing.20 “For [then] it becomes necessary to divide the integral whole and to say that on the one hand there is a proper human being who is dignified with the title of ‘Son,’ while on the other hand there is the proper Logos of God, who possesses by nature both the name and the exercise of sonship.”21 The Scripture does not say that the Word “united to himself the person of a human being but that he became flesh.”22

To Cyril, divine and human were so closely united within Jesus Christ that there was “only one subject or subsistent reality in Jesus.”23 The Virgin Mary may properly be called “God-bearer” because “the holy body which was born of her, possessed as it was of a rational soul, and to which the Logos was hypostatically united, is said to have had a fleshly birth.”24 The Son did not have his nature changed by taking on humanity, nor did one nature take precedence over the other, nor did the divine nature taste death when Jesus died, nor did the divine take on a human body as a type of avatar. Instead, Jesus Christ had both a human nature and a divine nature, and both were united hypostatically. This understanding of Christ builds on Irenaeus’ Christology which posits that Jesus had to be fully divine and fully human in order to heal humanity. If Jesus is less than human, less than divine, or even split into what Cyril calls “two sons”, his ability to heal humanity is limited or even blocked. Thus, the hypostatic union is a necessary doctrine of the Christian faith.

The Church accepted Cyril’s Christology. The Council of Chalcedon in 451 adopted a definition of Christ’s natures that was based on Pope Leo I’s letter to Flavian of Constantinople25 and on Cyril’s work to build a Christology based on Scripture, Christian tradition, reason, and experience. Cyril argued that Jesus Christ was fully divine and fully human, and his divine and human natures were united in one person. Despite needing no second birth, the divine Logos was united to the human Jesus at his conception by the power of the Holy Spirit and was subsequently born; the divine eternally begotten Son born in time to take on humanity for us and for our salvation.

1Joshua D. Allison, “St. Irenaeus’ Christology: Understanding the Work and Person of Jesus Christ,” unpublished manuscript, November 28, 2021.

2Richard A. Norris, Jr., “Introduction,” in The Christological Controversy, ed. and tr. by Richard A. Norris, Jr., (Minneapolis: Fortress Press, 1980), 26. I was unable to locate any reference to ἀνθρωποτόκος (anthropotokos, “bearer of humanity”) in the assigned readings for the class.

3Alister F. McGrath, Christian Theology: An Introduction, 25^th Anniversary Sixth Edition, (Hoboken: Wiley, 2016), 223. This text was assigned for ST6301: Interpreting the Christian Message and is cited here since the distinction between Theotokos and Christotokos helps explain Nestorius’ position.

4Nestorius of Constantinople, “First Sermon Against the Theotokos,” in Christological Controversy, 125.

5Nestorius, “Against the Theotokos,” 127.

6Nestorius, “Against the Theotokos,” 124.

7Nestorius, “Against the Theotokos,” 125.

8Nestorius, “Against the Theotokos,” 129. Scripture translation original to the text.

9Nestorius, “Against the Theotokos,” 129.

10Nestorius, “Against the Theotokos,” 128-129.

11Nestorius, “Against the Theotokos,” 130.

12Nestorius, “Second Letter to Cyril,” 137.

13Nestorius, “Second Letter to Cyril,” 138.

14Mike Higton, “Hypostatic Union” in The Cambridge Dictionary of Christian Theology ed. Ian A. McFarland, et al., (Cambridge: Cambridge University Press, 2011), 230.

15Cyril of Alexandria, “Second Letter to Nestorius,” in Christological Controversy, 132-133.

16Cyril, “Second Letter,” 133.

17Cyril, “Second Letter,” 133.

18Cyril, “Second Letter,” 133.

19Cyril, “Second Letter,” 134.

20Cyril, “Second Letter,” 134.

21Cyril, “Second Letter,” 134.

22Cyril, “Second Letter,” 134.

23Norris, “Introduction” in Christological Controversy, 28.

24Cyril, “Second Letter,” 135.

25A tome which lies beyond our scope here but bears mentioning due to its importance.

St. Irenaeus’ Christology: Understanding the Work and Person of Jesus Christ

The heresies of Gnosticism and Marcionism have had a lasting impact on Christianity. Pervasive, resilient, and syncretic, Gnosticism has encouraged the Church to write creeds and define doctrine while occasionally seeping into Christian belief. Marcionism also influenced the writing of creeds and other important documents, many of which are still important today. One of the earliest and most important documents is Exposure and Refutation of Knowledge Falsely So-Called (commonly known as Against Heresies), written by St. Irenaeus of Lyons (c. 130 – c. 202 ce). Against Heresies continues to influence Christian doctrine today. Using Scripture, Christian tradition, reason, and experience, Irenaus builds a defense against Marcionism and Gnosticism that is firmly founded on his Christology. Irenaeus’ Christology makes three important claims: that Christ came as the Second Adam to sum up (“recapitulate”) all things and thus redeem humanity, that Christ was truly human, and that Christ was truly divine.

As early as the second century, the Church found itself facing a problem: How could Jesus, who bled and died a shameful, painful death, be divine? How could Jesus, who worked miracles, arose from death, and ascended into heaven, be human? In other words, was Jesus only divine, only human, or some kind of mixture of both? This is the question of incarnation, or “the process by which God is understood to have become human flesh (i.e., taken on a human life) in Jesus of Nazareth.”1 The New Testament itself seems to be clear on the subject. The Gospels present Jesus as being both divine and human, and this claim is echoed in the epistles. Yet questions remained. How could God become human? How could God die?

Gnosticism was one attempt at a solution to the question. Gnosticism arose in the late first or early second century as a loose and hard to define group of beliefs and doctrines accumulated from various sources.2 Second century sects held that “the visible world [is] alien to the supreme God and as incompatible with truth as darkness with light.”3 They also asserted that “elect souls are divine sparks temporarily imprisoned in matter as a result of a precosmic catastrophe,” but that these sparks or souls are redeemed by a savior sent from the transcendent God.4 The savior’s teachings “awake the sleepwalking soul to a consciousness of its origins and destiny, and also include instructions how to pass the blind planetary powers which bar the soul's ascent to its celestial home.”5 This teaching or secret knowledge is called gnosis, from which the heresy draws its name.6 The two main problems that Gnosticism presents to Christianity are that it splits God into two, one evil and one good, and then re-frames God’s work in the world as a redemption from creation rather than a redemption of creation.7 For many years, one of our best sources of Gnostic thought was Against Heresies, along with other works from the same time period. In arguing against Gnosticism, Irenaeus gives us a Christology built on the theory of recapitulation and the idea that Christ was truly human and truly divine.

Irenaeus spends less time explicitly building his idea of recapitulation than he spends on the next two (namely, that Christ was both human and divine). Yet it is the basis for his Christology and appears throughout his work. Irenaeus argues that Christ was the Second Adam who successfully took on the same flesh, same temptations, etc. and thereby healed humanity’s sinful nature. In one poignant metaphor, Irenaeus compares Eve and Adam taking the fruit of the tree of the knowledge of good and evil with Jesus refusing to turn stones into bread in the wilderness: “For as at the beginning it was by means of food that [the enemy] persuaded man, although not suffering hunger, to transgress God’s commandments, so in the end he did not succeed in persuading him that was hungered to take that food which proceeded from God.”8 Throughout his writing, Irenaeus shows that where Adam failed, Christ succeeded. “He has therefore, in his work of recapitulation, summed up all things, both waging war against our enemy, and crushing him who had at the beginning led us away captives in Adam, and trampled upon his head . . . .”9 Irenaeus makes a comparison between the way sin entered the world through Eve and the way Christ was born of a human woman, “in order that, as our species went down to death through a vanquished man, so we may ascend to life again through a victorious one; and as through a man death received the palm [of victory] against us, so again by a man we may receive the palm against death.”10 For Irenaeus, recapitulation is important because it is the way that Christ redeems the sins of humanity. Key to Christ’s recapitulation of Adam is the fact that Christ had to be fully human and fully divine.

Irenaeus argues that in order to be truly human Jesus Christ had to take on human flesh by being born of a woman. To say otherwise would be to deny the relationship between Jesus and Adam. Further, it would mean that Jesus “appeared putatively as man when he was not man, and that he was made man while taking nothing from man.”11 Being made human without taking anything from humanity is problematic because it means that Christ is not truly human: “For if he did not receive the substance of flesh from a human being, he neither was made man nor the Son of man; and if he was not made what we were, he did no great thing in what he suffered and endured.”12 Besides, Irenaeus continues, why even bother to be born of Mary if he wasn’t going to take anything from her?13 Similarly, it was important that Jesus be born of Mary and not formed from dust again, “that there might not be another formation called into being, nor any other which should [require to] be saved, but that the very same formation should be summed up [in Christ as had existed in Adam], the analogy having been preserved.”14

Irenaeus seems to consider that Christ’s divinity is not under question, yet he does give us some useful guidance. He argues that the Word and Wisdom, the Son and the Spirit, were active in creation with the Father—a connection with our previous discussion about the Trinitarian nature of God.15 Irenaeus writes that “there are some who say that Jesus was merely a receptacle of Christ, upon whom the Christ, as a dove, descended from above . . . .”16 He appeals to the author of the Fourth Gospel, writing “that John knew the one and the same Word of God, and that He was the only begotten, and that He became incarnate for our salvation, Jesus Christ our Lord, I have sufficiently proved from the word of John himself.”17 He goes on to quote Matthew 1:20: “. . . an angel of the Lord appeared to [Joseph] in a dream and said, ‘Joseph, son of David, do not be afraid to take Mary as your wife, for the child conceived in her is from the Holy Spirit.’” He concludes, “we should not imagine that Jesus was one, and Christ another, but should know them to be one and the same.”18 He argues that a completely human parentage—being the earthly son of Joseph—would cause Jesus to be less than God. His reasoning is that Adam was formed “from untilled and as yet virgin soil . . . by the hand of God, that is, by the Word of God. . . .”19 Had Adam had human parentage and was thus born of human seed, then saying that Jesus was born of human seed would be reasonable. “But if the former was taken from the dust, and God was his Maker, it was incumbent that the latter also, making a recapitulation in himself, should be formed as man by God, to have an analogy with the former as respects his origin.”20

Irenaeus takes another tack with the idea that Jesus forgave sins—something that a human prophet cannot fully do, but which the Son of God has full authority to do. “[I]n what way can sins be truly remitted, unless that He against whom we have sinned has Himself granted remission "through the bowels of mercy of our God . . . ?”21 By remitting sins, Christ healed humanity and revealed himself as the Son of God.22 Only God can forgive sins, and Christ’s action thus proved that Jesus is God.23

Irenaeus’ Christology is that Jesus Christ came into the world as the Second Adam, taking on human nature to bring salvation and forgiveness to humanity. Yet Christ could not offer salvation and forgiveness without being divine. While he does not attempt to define the hypostatic union that later theologians would come to understand, he does see both natures as being equally important, equally visible, and equally manifest in the person of Jesus Christ. In arguing Christ’s divinity and humanity, Irenaeus not only answers the heretical leanings of Gnosticism and Marcionism, he also offers us a beautiful and vitally important Christology for believers today.

1“Incarnation” in The Cambridge Dictionary of Christian Theology, ed. Ian A. McFarland, et.al., (Cambridge: Cambridge University Press, 2011), 235.

2“Gnosticism” in Dictionary of Christian Theology, 199-200.

3John Myles Dillon, “Gnosticism,” The Oxford Classical Dictionary, (Oxford: Oxford University Press, 2012).

4Dillon, “Gnosticism” in Oxford Dictionary.

5Dillon, “Gnosticism” in Oxford Dictionary.

6There appears to be a great deal of controversy recently over the beliefs of Gnosticism, and even over whether it can rightly be named and defined at all.

7James Lee, “Gnosticism, 2^nd Century,” class handout for Christian Heritage I, September 13, 2021.

8Irenaeus, “Against Heresies,” in Ante-Nicene Fathers, vol. 1, ed. Alexander Roberts, James Donaldson, and A. Cleveland Cox, trans. Alexander Roberts and William Rambaut (Buffalo, NY: Christian Literature, 1885), revised and edited for New Advent by Kevin Knight, http://www.newadvent.org/fathers/0103420.htm, V.21.2. Christ’s hunger is also an important part of his proof that Christ was fully human, as we shall see.

9Irenaeus, “Against Heresies,” V.21.1.

10Irenaeus, “Against Heresies,” V.21.1.

11Irenaeus, “Against Heresies,” III.22.1.

12Irenaeus, “Against Heresies,” III.22.1. This idea was also expressed by Gregory of Nazianzus (ca. 329–390), Archbishop of Constantinople in the fourth century: “For that which he has not assumed he has not healed; but that which is united to his Godhead is also saved.” Gregory of Nazianzus, “Epistle 101:To Cledonius the Priest Against Apollinarius” in Ante-Nicene Fathers, vol. 1, ed. Alexander Roberts, James Donaldson, and A. Cleveland Cox, trans. Alexander Roberts and William Rambaut (Buffalo, NY: Christian Literature, 1885), revised and edited for New Advent by Kevin Knight, https://www.newadvent.org/fathers/3103a.htm

13Irenaeus, “Against Heresies,” III.22.2. “Still further, if He had taken nothing of Mary, He would never have availed Himself of those kinds of food which are derived from the earth, by which that body which has been taken from the earth is nourished; nor would He have hungered, fasting those forty days, like Moses and Elias, unless His body was craving after its own proper nourishment . . . .” Irenaeus’ emphasis on Jesus eating real food, being weary, and bleeding is interesting because it calls on both experience and reason to show that only a human could suffer from these things.

14Irenaeus, “Against Heresies,” III.22.10.

15Irenaeus, “Against Heresies,” IV.20.

16Irenaeus, “Against Heresies,” III.16.1.

17Irenaeus, “Against Heresies,” III.16.2.

18Irenaeus, “Against Heresies,” III.16.2.

19Irenaeus, “Against Heresies,” III.22.10.

20Irenaeus, “Against Heresies,” III.22.10.

21Irenaeus, “Against Heresies,” V.17.1.

22Irenaeus, “Against Heresies,” V.17.3.

23Irenaeus, “Against Heresies,” V.17.3.