Surely the most important question in the world is the one that forms the title for this article: ‘Who is Jesus?’. Answering that question is the task of what we call ‘Christology,’ a word that means ‘the study of Christ’ and that refers to the branch of Christian theology dealing with the person of Christ.

Typically, when we are asked this question, we answer by saying something like: ‘He is fully God and fully man.’ This is true, of course, but as an answer to the question of who Jesus is, it is more ambiguous than we might realize. According to a story (I do not know whether it is really a true story, but it certainly could have happened many times), a pastor in the nineteenth century was on trial for heresy. The people examining him asked him what they thought was a sufficiently specific question: ‘Do you deny the divinity of Christ?’ His answer, according to the story, was, ‘I’ve never denied the divinity of any man, let alone Christ.’

Notice two things about this answer. First, the pastor is not using the word ‘divinity’ in the same way we do when we say that Christ is divine. For him, ‘divinity’ means little more than that Christ has a special connection to God or embodies some aspects of God’s character in a unique way. It certainly does not mean that he thinks Christ is God, or he would not ascribe divinity to everyone. Second, the pastor’s forthrightness enables us to see that his view of Christ is insufficient. But suppose he had simply answered, ‘No, I do not deny the divinity of Christ.’ Would the examiners have asked further questions to see what he meant by affirming that Christ was divine? Would we inquire further, or would we be satisfied with the affirmation of Christ’s divinity, without trying to find out what was meant by that?

Today, many people affirm the divinity of Christ. Indeed, anyone who calls himself a Christian at all must affirm the divinity of Christ in some sense. But like the nineteenth-century pastor in the story, many people today—including many pastors and church leaders—interpret what it means for Christ to be divine very differently from the way the Bible and the Christian tradition have interpreted it. But because we are often satisfied with the mere statement, ‘Christ is divine and human,’ we often fail to probe more deeply into what a person means by that, in comparison to what the Bible means by that, and what the church has meant by that for most of its history. Let’s turn our attention, then, to the New Testament and to the church’s early reflections on the Scriptures.

Jesus in the New Testament: A Few Key Passages

Matthew 16:13-20

We know how significant is the question ‘Who is Jesus?’ because Jesus himself asked it. In Matthew 16, he asks the disciples who the people think he is. After they answer, Jesus then poses the much more poignant question, ‘Who do you say I am?’ (Matt. 16:15).  Peter’s memorable reply is, ‘You are the Christ, the Son of the living God’ (Matt. 16:16). Notice that this answer doesn’t focus on the fact that Jesus is a man (which was surely obvious), nor does it focus on the fact that he is God per se. Instead, Peter focuses on two concepts familiar to first-century Jews—the concept of ‘Messiah’ (which is ‘Christ’ in Greek) and the concept of ‘Son of God.’

Throughout the Old Testament, the people of Israel had been expecting God to send a man who would crush the head of the serpent and undo the effects of the fall. At first, this man was called the ‘Seed’ (see Gen. 3:15), and as time went on, he began to be called the ‘Messiah,’ which means ‘anointed one.’ This promised Messiah was to come from the descendants of Eve, of Abraham, of Isaac (not Ishmael), of Jacob (not Esau), of Judah, of David. The Messiah was to be a prophet (See Deut. 18:15-22), and more strikingly, an eternal king and an eternal priest (see Ps. 110). The eternity of his service as king and priest was an early hint that he would be more than just a man. Later in the Old Testament, it became clearer that he would be himself eternal (and thus divine). Micah declared in 5:2 not only that the Messiah would be born in  Bethlehem, but that even though he would come forth from Bethlehem, his ‘goings forth’ were from of old, from days of eternity. (This seems to be what John the Baptist is referring to when he declares in John 1:29, ‘After me comes a man who ranks before me, because he was before me.’) The Messiah, then, is not only a man sent from God to be a prophet, priest, and king; he is somehow going to be God himself. Also in the Old Testament, the idea of Messiah is linked to the idea of ‘Son of God.’ The kings of Israel were called sons of God, and the Messiah, as the eternal king, will be Son of God in a unique way.

At the time Peter links these ideas by calling Jesus both ‘Messiah’ and ‘Son of God,’ he and the other disciples have spent months, maybe a couple of years, with Jesus. They have watched him heal, heard him teach, and wondered, ‘Who therefore is this man?’ Peter and the others are now beginning to realize that he is the Messiah, and that he is not just a human Messiah but the Son of God in a unique way, a greater way than any mere man could be called God’s son. Indeed, the first three Gospels, and especially Mark, can be seen as—among other things—following the disciples’ journey of discovery about Jesus. As they follow him, they realize that he is more than just a great teacher. He is the Messiah, and greater than and different from what they were expecting in the Messiah.

John 1:1-18

Rather than starting with events surrounding the birth of Christ (as in Matthew and Luke) or his announcement that the kingdom of God is at hand (as in Mark), John begins with the Word, the Logos, in his eternal relationship to God. ‘In the beginning was the Word, and the Word was with God, and the Word was God’ (John 1:1-2). Here he establishes the eternity of the Word, the distinction between the Word and God such that they can be ‘with’ each other, and the identity of the Word as God. Shortly thereafter, John famously affirms: ‘The Word became flesh and dwelt among us, and we have seen his glory, glory as of the only Son from the Father, full of grace and truth’ (John 1:14). Here John makes clear that the birth of the Word in flesh is not the beginning of his existence. He has always been with God, and has always been God. He has always been the unique Son from the Father. But now that he has become human, we can see him for who he is.

Just before this famous assertion, John has linked the Word’s unique status as God’s Son to our sonship (and daughtership!) to God. He writes, ‘To all who did receive him, who believed in his name, he gave the right to become children of God, who were born, not of blood nor of the will of the flesh nor of the will of man, but of God’ (John 1:12-13). Here we see that John affirms that those who believe in Jesus’ name become ‘children’ of God, in a non-fleshly, non-physical way. Jesus is the Word, the one who has eternally been with God, the unique Son of the Father. We are somehow brought into that relationship that he has with the Father, so that we can be called children of God as well.

Philippians 2:5-11

The New Testament letters further explain the picture of Jesus we receive from the Gospels, and perhaps Philippians 2 is the clearest passage. Here, Paul enjoins the readers to an attitude of humility, because of the humility that Christ has shown. He elaborates, ‘Who, though he was in the form of God, did not count equality with God a thing to be grasped, but made himself nothing, taking the form of a servant, being born in the likeness of men. And being found in human form, he humbled himself by becoming obedient to the point of death, even death on a cross’ (Phil. 2:5-8) This passage shows the downward movement of God’s Son. He was equal with God, yet he humbled himself by becoming human, and even more so by consenting to die in the most shameful way possible at the time, by crucifixion. This downward movement was followed by an upward movement: ‘Therefore God has highly exalted him and bestowed on him the name that is above every name, so that at the name of Jesus every knee should bow, in heaven and on earth an under the earth, and every tongue confess that Jesus Christ is Lord, to the glory of God the Father’ (Phil. 2:9-11).

This passage, which may be a quotation from an ancient hymn used in the earliest church’s worship, lays out the grand drama of the Son’s action for our redemption. From other passages in Scripture, we recognize that his humiliation did not imply that he stopped being God. Rather, he became human while remaining God, died as a man while remaining God, and was exalted as a man back to the position of honor that, as God, he had never left. To state this differently, Jesus started as only God, became human so that he was God and man, died, was exalted, and will one day be recognized as Lord by everyone. His humiliation and exaltation enable us to recognize who he has always been—God’s Son.

These passages, and many other like them, provide the basic structure for our understanding of who Jesus Christ is. He is not merely a man who is divine in some sense. He is not a man who was elevated to the status of God. He started out as God, as the unique Son of God the Father. Indeed, the very fact that we call God ‘Father’ implies that he has a child, and while it is true that we are God’s children, we haven’t always been here. If God has always been a Father, then he must have always had a Child, and he has. The Word, the Son, Jesus, has always been with the Father. And yet that eternal Son of God has entered time and space by becoming human in order to redeem us, to bring us back to God his Father, so that his Father might become our Father as well.

The Early Church’s Reflection on Christ

As great Christian thinkers reflected on these passages and others, their focus was on the relation between who Christ is and what Christ does to accomplish our salvation. Jaroslav Pelikan has correctly called attention to this connection in his five-volume work The Christian Tradition, by using as an organizing rubric the statement, ‘Christ had to be who he was to do what he did.’ I would like to expand that statement further, to the following: ‘Christ has to be who he is to do what he does to give us the kind of salvation that we have.’

If salvation were merely a thing, a set of goods or benefits, then such a thing could be easily transferred. God could entrust it to someone else, and then that someone could pass along this set of goods or benefits to others. But if salvation is more than a set of goods, if it is a personal connection to God, then only God can give such a personal relationship to people. If you give me something as a gift, I can turn around and give that thing to someone else. But if you give me the gift of yourself, I cannot give you to someone else. Only you can do that. In the case of the gift of fellowship with God, only God can grant it. This implies that the person who gives us the right to be children of God, Jesus, has to be God in order to bring us into relationship with God. A mere man with a special connection to God, or a man inspired by God, would not truly be God and could not save us, if this is what we mean by salvation.

Another way of looking at the same issue is to ask whether we can rise up to God ourselves. If the answer to that question is ‘yes,’ then all we need is a leader, someone who can give us an example to follow and show us the way to rise up to God. We could then save ourselves by following that person’s example. In that case we could essentially earn our own salvation. But if we can’t rise up to God, then if we are to be saved, God has to come down to us. So again, the one who saves us, Jesus, has to be God.

Following this line of reasoning, the church in the second and third centuries affirmed the central truth that God the Son, fully equal to the Father, has personally come down to earth to save us. For example, in the late second century, Irenaeus of Lyons (in what is today France) combatted the heresy of Gnosticism (which, among other things, saw the divine Christ and the human Jesus as two separate persons) by writing this:

‘The Gnostics allege that one Being suffered and was born, and that this was Jesus; but that there was another who descended upon Him, and that this was Christ, who also ascended again… Their doctrine departs from Him who is truly God, being ignorant that His only-begotten Word … is Himself Jesus Christ our Lord, who did also suffer for us, and rose again on our behalf, and who will come again in the glory of His Father…’
Irenaeus, Against Heresies 3.16.6 (ca. 180)      

Similarly, at about the same time Tertullian of Carthage (in modern Tunisia) responded to Marcion’s denial that God the Son really died on the cross by asserting: ‘But answer me this, you murderer of truth: Was not God truly crucified? And being truly crucified, did he not truly die? And having truly died, was he not truly raised?’ (Tertullian, On the Flesh of Christ 5.2 [ca. 190]).

The First Great Challenge to this Consensus: Arianism

The church’s consensus—that the eternal Son of God truly became human, was born, and died for our salvation—was challenged in various ways in the early centuries of Christianity. The most serious of these challenges came from Arius, a presbyter in Alexandria (Egypt) in the early fourth century. Arius held to a view of salvation as humanity’s rising up to God, and therefore in his understanding, Jesus did not have to be fully God. A being in between God and humanity would suffice as a leader to show us the way by which we could rise up to God ourselves. Furthermore, Arius took very seriously the idea that there is only one God, and so he and his followers argued that the Son was not fully God and eternal, but a subordinate being, the first and greatest created being. (You may notice that modern Jehovah’s Witness theology sounds kind of like ancient Arianism.) Around the year 318 or 319, Arius wrote the following:

We know one God—alone unbegotten, alone everlasting, alone without beginning, alone true, alone possessing immortality, alone wise, alone good, alone master, … who begot an only-begotten Son before eternal times, through whom he made the ages and everything. But he begot him not in appearance but in truth, having submitted him to his own will, an immutable and unchangeable perfect creature of God…. The Son, begotten by the Father, created and founded before the ages, was not before he was begotten. Rather, the Son begotten timelessly before everything, alone was caused to subsist by the Father. For he is not everlasting or co-everlasting or unbegotten with the Father.
Arius, Letter to Alexander of Alexandria

Here we see that Arius draws a distinction between God and the Son, and calls the Son a creature. In one sense, this seems perfectly reasonable: if there is really only one God who made everything, then anyone else—like the Son—must be a creature, and if the Father has a Son, then the Son would seem to have come into existence later than the Father. But Arius fails to realize several things: that the Son is eternal and therefore the same God as the Father, that ‘begetting’ is different for God than for human beings (instead of implying that the Son is younger, the word ‘begotten’ is a way of describing the unique filial relationship of the Son to the Father), and that salvation as the Bible describes it could not happen if the Son were not equal to the Father. Arius’ Jesus could merely lead us up to God. He could not bring us to God, because he is not God himself.

The Church’s response to Arius was swift and direct. He was condemned at a council held in Nicaea (in what is today northwestern Turkey) in 325, what we call the ‘First Ecumenical Council.’ Later, Athanasius (the key leader of the church during the Arian controversy) wrote this:

Arius dared to say, ‘The Word is not true God. Even if he is declared God, he is not true God. By sharing grace, he is declared God only in name, just as all the others….’ But we speak freely about the religious faith on the basis of the divine Scriptures; we place it as a light on the lampstand, saying, ‘He is by nature true Son and legitimate from the Father, peculiar to his substance, the only-begotten Wisdom and true and only Word of God. Therefore he is true God, homoousios with the true Father.’
Athanasius, Against the Arians 1.6, 1.9 (ca. 340)

In this passage, the word homoousios was a word that the Council of Nicaea had used in 325 to indicate that Jesus is of the same substance as the Father. He is not a semi-divine being as Arius thought, but fully equal to the Father, such that they (and the Holy Spirit) constitute one God rather than three.

Even though the church clearly recognized that Arius was wrong about Jesus, the issues he and his followers raised precipitated half a century of intense discussion. The end result of that discussion was a council held in Constantinople (modern-day Istanbul) in 381 (which we call the ‘Second Ecumenical Council’), which ratified a creed that has gone on to be the Christian church’s most important doctrinal statement (and which we now call the Nicene Creed). The creed reads as follows:

We believe in one God, Father, all-sovereign, maker of heaven and earth, of all things seen and unseen.

And in one Lord Jesus Christ, the only-begotten Son of God, who was begotten from the Father before all the ages, light from light, true God from true God, begotten, not made,  homoousios with the Father, through whom all things came into existence, who because of us men and our salvation came down from heaven, and was incarnated by the Holy Spirit and the virgin Mary, and was made man, was crucified on our behalf by Pontius Pilate, and suffered, and was buried, and arose on the third day according to the Scriptures, and ascended into heaven, and is seated at the right of the Father, and is coming again with glory to judge the living and the dead, of whose kingdom there will be no end.

And in the Holy Spirit, the Lord, who makes us alive, who proceeds from the Father, who is worshiped and glorified together with the Father and the Son, who has spoken through the prophets.

In one holy, catholic, and apostolic Church. We confess one baptism for the forgiveness of sins. We await the resurrection of the dead and the life of the coming age. Amen.

In this creed, notice the confession of faith in God the Father, in the Son of God, Jesus Christ, and in the Holy Spirit. Because the Son is homoousios (of the same substance) with the Father, he is God just as the Father is. And because the Spirit is worshiped and glorified together with the Father and the Son, he is God just as they are. The three persons constitute a single God, not three separate gods. Equally important, notice that the only-begotten Son of God, the one who is true God from true God, has come down and become human for our salvation. In order to save us, he had to be fully God, but he also had to come down by becoming human as well. Jesus is not merely divine and human in some sense. He is God the Son who has become human in order to save us. Here the church is following very carefully the lines laid down in John 1 and Philippians 2.

The Second Great Challenge to this Consensus: Nestorianism

One might have thought that the Nicene Creed would have resolved once and for all the question of who Jesus is. But in the latter fourth century, a man by the name of Apollinaris—while attempting to be faithful to the Nicene faith—adopted a view of Christ’s humanity that the church recognized as inadequate. Apollinaris argued that to be both spiritual and physical is to be human, and since the Word was already spiritual, if he simply took upon himself a human body, that made him fully human. In response, the church recognized correctly that to be fully human, he needed not merely a body, but a human mind, human emotions, etc. Gregory of Nazianzus (in central Turkey) argued most persuasively that whatever aspect of humanity the Son did not take upon himself is not touched by salvation. ‘The unassumed is unhealed,’ but there is no aspect of what it means to be human that was unassumed, and thus no aspect of humanity to which salvation does not reach.

This might have been the end of the matter, except that the problems created by Apollinaris’ thought led a few people in the church to re-think the whole notion of salvation and to re-adopt a model in which we rise up to God. Theodore of Mopsuestia (in southeastern Turkey) wrote boldly of human history as a march from what he called the first age (an age of mutability, sin, mortality, and imperfection) to the second age (an age of perfection, sinlessness, and immortality). Such a view of human progress meant that Theodore—like Arius previously—did not believe humans needed God to come down to save us. He thought we could rise up to God if we had a sufficient example. Unlike Arius, Theodore firmly believed that the Word is equal to the Father, but the similarity of his thought about salvation to Arius’ led him to argue that Jesus is not God the Word. Instead, Jesus is a man (Theodore called him the ‘assumed man’) in whom the Word dwells, a man who has a special connection to God the Word.

Notice here how similar Theodore’s thought is to the later modern idea of the upward progress of humanity—most clearly expressed in the nineteenth century. It is no surprise that the nineteenth century also saw many Christians adopt a view of Christ like that of Theodore. They believed that he was a man with a special connection to God, not that he was God the Son living on earth as a man.

So how did the church respond to Theodore? Well, he had the good fortune to live in a quite obscure place, and during his lifetime he attracted little attention. But in the year that Theodore died, 428, his student Nestorius became bishop of Constantinople and began preaching before the entire Christian world the doctrine of his teacher. The following are excerpts from two different sermons of Nestorius, both preached in the year 428: ‘We preserve the unconfused conjunction of the natures. We confess God in a man; we worship the man who is venerated together with almighty God by virtue of the divine conjunction’ (Sermon 8). ‘I revere the one who is borne because of the one who carries him, and I worship the one I see because of the one who is hidden. God is undivided from the one who appears, and therefore I do not divide the honor of that which is not divided. I divide the natures, but I unite the worship’ (Sermon 9).

In these excerpts, notice that Nestorius seems to be orthodox according to our ordinary ways of thinking, because he speaks of ‘two natures’ in Christ. But if we look more carefully, two statements stand out. He confesses ‘God in a man,’ and he reveres ‘the one who is borne because of the one who carries him.’ Both of these assertions demonstrate that for Nestorius, as for Theodore before him, Jesus is not the same person who has always been the Father’s Son. He is a man in whom God dwells; he is the one borne by God, with a connection to God. The fact that Nestorius unites the worship and reveres the man because of the Word who indwells him does not change the fact that the man Jesus is not the same person who is God’s eternal Son.

So what is actually wrong with Theodore’s and Nestorius’ thought? Two major things: It makes the so-called ‘divinity of Christ’ little more than divine indwelling, and it thus places our salvation in the hands of one who is not truly God. A man indwelt by God the Word is not really any different than a person indwelt by the Holy Spirit. Every believer is indwelt by God (the Holy Spirit), but such indwelling does not make us able to save anyone else. A divinely-indwelt man can’t save us. Only God himself can save us, and Nestorius’ Christ is not, as a person, God the Son.

The major figure in the church who responded to Theodore and Nestorius was Cyril of Alexandria, who emphasized that salvation was a matter not of our rising up to a higher plane of existence, but of God’s coming down to bring us to himself. He argued further that our salvation is linked to Christ’s own relationship with the Father: he is the true, natural Son of God, and we become sons and daughters of God by adoption. As Cyril comments on John 1:12-13 (a passage that I quoted and discussed above), he writes:

For when he had said that authority was given to them from him who is by nature Son, to become sons of God, and had hereby first introduced that which is of adoption and grace, he can afterwards add without danger [of misunderstanding] that they were begotten of God; that he might show the greatness of the grace which was conferred on them, gathering as it were into natural fellowship those who were alien from God the Father, and raising up the slaves to the nobility of their Lord, on account of his warm love towards them.
Cyril of Alexandria, Commentary on John, 1:13

The crucial phrase in this passage is ‘natural fellowship.’ Cyril uses this phrase to refer to the fellowship that the persons of the Trinity have with one another because they share the same nature, because they constitute the same God. But here and elsewhere in his writings, he argues that God grants believers to share in that very same fellowship. God does not cause us to become equal to him in any way at all (he has just denied that possibility earlier in his commentary), but even so, he grants us a share in the very fellowship that the persons of the Trinity enjoy. Only God’s true, natural Son could grant us this by making us sons through adoption.

From Cyril’s writings, it becomes clear that the crucial point of Christology is not merely that Christ be one person or that he have two natures, although of course those things are true of him. The crucial point is that he be the same person who has always been the eternal Son of God. At the end of the day, Nestorius’ Christ is not God the Son. The baby born of Mary is not—according to Nestorius—the eternally-begotten Son of God. Cyril argues—correctly—that the Word before the incarnation and Jesus afterwards are the same person. He who once was merely God is now God and human as well, but he is still the same person. If one does not say this, then one is implying that our salvation is not accomplished by God’s coming down to us. And I believe that Cyril’s thought represented and expressed the consensus of the entire church.

The Chalcedonian Definition

The Nestorian controversy led to two ecumenical councils, the Third at Ephesus (western Turkey) in 431, which was very politically  messy and did not permanently solve the problem, and the Fourth at Chalcedon (near Nicaea in northwestern Turkey) in 451, which produced the church’s second-most important doctrinal pronouncement, the Chalcedonian Definition. Today people often think of the Chalcedonian Definition as a compromise document, designed to mediate between ‘Alexandrian’ emphases (like those of Athanasius and Cyril) and ‘Antiochene’ emphases (like those of Theodore and Nestorius). The central feature of the document, in the minds of many modern scholars is the portion highlighted in yellow as I quote it just below:

Therefore, following the holy fathers, we all unite in teaching that we should confess one and the same Son, our Lord Jesus Christ.

This same one is perfect in deity, and the same one is perfect in humanity; the same one is true God and true man, comprising a rational soul and a body. He is of the same substance as the Father according to his deity, and the same one is of the same substance with us according to his humanity, like us in all things except sin. He was begotten before the ages from the Father according to his deity, but in the last days for us and our salvation, the same one was born of the virgin Mary, the bearer of God, according to his humanity.

He is one and the same Christ, Son, Lord, and Only-begottenwho is made known in two natures united unconfusedly, unchangeably, indivisibly, inseparably. The distinction between the natures is not at all destroyed because of the union, but rather the property of each nature is preserved and concurs together into one prosopon and hypostasis.

He is not separated or divided into two prosopa, but he is one and the same Son, the Only-Begotten, God the Logos, the Lord Jesus Christ.

This is the way the prophets spoke of him from the beginning, and Jesus Christ himself instructed us, and the Council of the fathers has handed [the faith] down to us.

The portion in italics emphasizes the two natures and the one person (prosoponand hypostasis are both words for ‘person’), and the terminological clarity afforded by this statement is an important part of Chalcedon’s contribution to our understanding of Christ. This statement in italics, however, is not the main thing the definition is affirming. Instead, the main point—reiterated eight timesin one paragraph and highlighted in bold—is that the baby born from Mary is the same one who has always been the Son of God. The bishops gathered at Chalcedon are affirming that in order for us to be saved, God himself had to come down to save us. Therefore, not only does the Word have to be God, but Jesus and the Word have to be the same person. If Jesus is not the Word, but is instead a man in whom the Word dwells, then God has not come down to save us, and therefore we are not saved. But Jesus is God the Word who has become human for our sake. This is the central truth the church sought to proclaim.

Therefore, I often assert that the main point of biblical and patristic Christology is not whether Christ is one person with two natures, but who that one person is. It is not enough simply to assert that Christ is one person and that he has two natures. Nestorius affirmed that, yet his Christ was a different one from the real Christ who alone can save us. Many people in the last two hundred years—like the pastor in the story with which I began—have affirmed that Christ is one person in two natures, but they have not meant by this that he is the eternal Son of God who has become human. The crucial truth—the saving truth—is that for us to be saved, God had to come down to save us. So the one who came down had to be truly God, just as fully God as the Father. Furthermore, the equally crucial truth is that the Son had to come all the way down to us—by becoming human so as to live, die, and be raised as a man. If this is the kind of salvation that Scripture says we need, and have, then this is the kind of Savior that we must have. And according to both the Bible and the church’s historic consensus, this is the Savior whom we do have.

Who is Jesus? He is God’s eternal, beloved Son who has become human while remaining who he already was, in order to accomplish our salvation.

Donald Fairbairn