Equally amazing to the doctrine of the Trinity is the doctrine of the Incarnation--that Jesus Christ is God and man, yet one person, forever. As J.I. Packer has said: "Here are two mysteries for the price of one--the plurality of persons within the unity of God, and the union of Godhead and manhood in the person of Jesus. ...Nothing in fiction is so fantastic as is this truth of the Incarnation," writes contemporary theologian J.I. Packer.1
The early church considered the Incarnation to be one of the most important truths of our faith. Because of this, they formulated what has come to be called the Chalcedonean Creed, a statement which sets forth very what we are to believe and what we are not to believe about the Incarnation. This creed was the fruit of a large council that took place from October 8 to November 1, 451, in the city of Chalcedon and "has been taken as the standard, orthodox definition of the biblical teaching on the person of Christ since that day by" all the major branches of Christianity.2 There are five main truths with which the creed of Chalcedon summarized the biblical teaching on the Incarnation.
1. Jesus has two natures -- He is God and man.
2. Each nature is full and complete -- He is fully God and fully man.
3. Each nature remains distinct.
4. Christ is only one Person.
5. Things that are true of only one nature are nonetheless true of the Person of Christ.
A proper understanding of these truths clears up much confusion and many difficulties we may have in our mind. How can Jesus be both God and man? Why doesn't this make Him two people? How does His Incarnation relate to the Trinity? How could Jesus have hungered (Matthew 4:2) and died (Mark 15:37) when He was on earth, and yet still be God? Did Jesus give up any of His divine attributes in the Incarnation? Why is it inaccurate to say that Jesus is a "part" of God? Is Jesus still human now, and does He still have His human body?
Jesus has two natures -- God and man
The first truth we need to understand is that Jesus is one Person who has two natures a divine nature and a human nature. In other words, Jesus is both God and man. We will look at each nature accordingly.
Jesus is God
The Bible teaches that Jesus is not merely someone who is a lot like God, or someone who has a very close walk with God. Rather, Jesus is the Most High God Himself. Titus 2:13 says that as Christians we are "looking for the blessed hope and the appearing of the glory of our great God and Savior, Christ Jesus." Upon seeing the resurrected Christ, Thomas cried out, "My Lord and my God!" (John 20:28). Likewise, the book of Hebrews gives us God the Father's direct testimony about Christ: "But of the Son He says, 'Thy throne, O God, is forever and ever" and the gospel of John calls Jesus "the only begotten God" (John 1:18).
Another way the Bible teaches that Jesus is God is by showing that He has all of the attributes of God. He knows everything (Mt 16:21; Luke 11:17; John 4:29), is everywhere (Matthew 18:20; 28:20; Acts 18:10), has all power (Mt 8:26, 27; 28:18; Jn 11:38-44; Lk 7:14-15; Revelation 1:8), depends on nothing outside of Himself for life (Jn 1:4; 14:6; 8:58), rules over everything (Mt 28:18; Rev 19:16; 1:5) never began to exist and never will cease to exist (John 1:1; 8:58), and is our Creator (Colossians 1:16). In other words, everything that God is, Jesus is. For Jesus is God.
Specifically, Jesus is God the Son
In order to have a more complete grasp of Christ's incarnation, it is necessary to have some sort of understanding of the Trinity. The doctrine of the Trinity states that God is one being, and this one God exists as three distinct Persons. This means, first of all, that we must distinguish each Person of the Trinity from the other two. The Father is not the Son or the Holy Spirit, the Son is not the Holy Spirit or the Father, and the Holy Spirit is not the Father or the Son. They are each a distinct center of consciousness, a distinct form of personal existence. Yet, they all share the exact same divine nature/essence. Thus, the three persons are one being. The divine being/essence is not something that is divided between the Persons, each Person receiving one-third. Rather, the divine being is fully and equally possessed by all three Persons such that all three Persons are each fully and equally God.
How does the fact that God is three Persons in one Being relate to the incarnation? To answer this, let's consider another question. Which Person became incarnate in Jesus Christ? All three? Or just one? Which one? The Biblical answer is that only God the Son became incarnate. The Father did not become incarnate in Jesus, and neither did the Holy Spirit. Thus, Jesus is God, but He is not the Father or the Holy Spirit. Jesus is God the Son.
The truth that it is only God the Son who became incarnate is taught, for example, in John 1:14, which says "And the Word became flesh and dwelt among us, and we beheld His glory, glory as of the only begotten from the Father, full of grace and truth." In context, the word is God the Son (cf. vv. 1, 18, and 3:16). Thus, it wasn't the Father or the Holy Spirit who became man, but God the Son.
Likewise, at Jesus' baptism we see the Father affirming "Thou art My beloved Son, in Thee I am well-pleased" (Luke 3:22). He did not say, "You are me, and with myself I am well-pleased." Rather, the Father affirmed that Jesus is the Son, His Son, and that Jesus is well-pleasing to Him. In this same verse we also see that the Holy Spirit is distinct from the Father and the Son, for the Holy Spirit is present in "bodily form like a dove."
Why is it important to know that Jesus is specifically God the Son? For one thing, if we do not understand this we will be mistaken about the very identity of our savior. Further, it greatly affects how we relate to our triune God. If we think that Jesus is the Father and/or the Holy Spirit, we will be greatly misguided and confused in our prayers. Last, it is considered heresy to believe that the Father became incarnate in Jesus.
Jesus is man
It should be obvious that if Jesus is God, then He has always been God. There was a never a time when He became God, for God is eternal. But Jesus has not always been man. The fantastic miracle is that this eternal God became man at the Incarnation approximately 2,000 years ago. That's what the Incarnation was--God the Son becoming man. And its this great even that we celebrate at Christmas.
But what exactly do we mean when we say that God the Son became man? We certainly do not mean that He turned into a man, in the sense that He stopped being God and started being man. Jesus did not give up any of His divinity in the Incarnation, as is evident from the verses we saw earlier. Rather, as one early theologian put it, "Remaining what He was, He became what He was not." Christ "was not now God minus some elements of His deity, but God plus all that He had made His own by taking manhood to Himself."3 Thus, Jesus did not give up any of His divine attributes at the Incarnation. He remained in full possession of all of them. For if He were to ever give up any of His divine attributes, He would cease being God.
The truth of Jesus' humanity is just as important to hold to as the truth of His deity. The apostle John speaks strongly anyone that denying that Jesus is man is of the spirit of the anti-Christ (1 John 4:2; 2 John 7). Jesus' humanity is displayed in the fact that He was born as a baby from a human mother (Luke 2:7; Galatians 4:4), that He became weary (John 4:6), thirsty (John 19:28), and hungry (Matthew 4:2), and that He experienced the full range of human emotions such as marvel (Matt. 8:10), weeping, and sorrow (John 11:35). He lived on earth just as we do.
Jesus is a sinless man
It is also essential to know that Christ does not have a sinful nature, and neither did He ever commit sin -- even though He was tempted in all ways (Hebrews 4:15). Thus, Jesus is fully and perfectly man, and has also experienced the full range of human experience. We have a Savior who can truly identify with us because He is man, and who can also truly help us in temptation because He has never sinned. This is an awesome truth to cherish, and sets Christianity apart from all other religions.
Each nature is full and complete
Having seen the biblical basis that Jesus is both God and man, the second truth that we must recognize is that each of Christ's natures is full and complete. In other words, Jesus is fully God and fully man. Another helpful way to say it is that Jesus is 100% God and 100% man.
Jesus is fully God
We saw earlier that each Person of the Trinity is fully God. The three Persons of the Trinity are not each one-third of God, but are each all of God. Thus, Jesus is fully God since He is God the Son incarnate. This means that everything that is essential to being God is true of Jesus. Jesus is not part of God, or one-third of God. Rather, He is fully God. "For in Him all the fullness of Deity dwells in bodily form" (Colossians 2:9).
Jesus is fully man
It is also important to recognize that when we say that Jesus is man, we do not simply mean that He is partially man. We mean that He is fully human -- everything that belongs to the essence of true humanity is true of Him. He is just as truly human as the rest of us.
The fact that Jesus is truly and fully human is clear from the fact that He has a human body (Luke 24:39), a human mind (Luke 2:52), and a human soul (Matthew 26:38). Jesus does not just look like a man, He does not just have some aspects of what is essential for true humanity but not others, but possess full humanity.
It is helpful to be aware of the false views concerning Christ. For if we have a grasp of what we are not to believe, it will give us a fuller picture of what we are to believe. One of the false views that was rejected at the council of Chalcedon taught that "the one person of Christ had a human body but not a human mind or spirit, and that the mind and spirit of Christ were from the divine nature of the Son of God."4 Since this view did not believe that Jesus has a human mind and spirit, it in effect denied that Christ is fully and truly man. Rather, it presented Christ as a sort of half-man who has a human body, but whose human mind and soul were replaced by the divine nature. But as we saw earlier, Jesus is just as fully human as the rest of us, for just as He has all of the essential elements of Godhead, He has all the essential elements of human nature a human body, a human soul, a human mind, a human will, and human emotions. His human mind was not replaced by His divine mind. Rather, He has both a human and divine mind. For these reasons, it can be misleading to use phrases such as "Jesus is God in a body" or "Jesus is God with skin on."
Jesus will be fully God and fully man forever
For most people it is obvious that Jesus will be God forever. But for some reason it escapes a lot of us that Jesus will also be man forever. He is still man right now as you read this and will be forever. The Bible is clear that Jesus rose physically from the dead in the same body that had died (Luke 24:39) and then ascended into heaven as a man, in His physical body (Acts 1:9; Luke 24:50-51). It would make no sense for Him to have done this if He was simply going to ditch His body and stop being man when He arrived in heaven.
That Christ continued being man, with a physical body, after His ascension is confirmed by the fact that when He returns, it will be as man, in His body. He will return physically. Philippians 3:21 says that at His Second Coming, Christ "will transform the body of our humble state into conformity with the body of His glory." This verse is clear that Jesus still has His body. It is a glorified body, which Paul calls "the body of His glory." And when Christ returns, He will still have it because this verse says that He will transform our bodies to be like His. Both Jesus and all Christians will then continue living together in their bodies forever, because the resurrection body cannot die (1 Corinthians 15:42) because it is eternal (2 Corinthians 5:1).
Why did Jesus become man, and why will He be man forever? The book of Hebrews says that it was so that Christ could be an adequate Savior who has all that we need. "He had to be made like His brethren in all things, that He might become a merciful and faithful high priest in things pertaining to God, to make propitiation for the sins of the people" (2:17). First, notice that Jesus became man so that He could die for our sins. He had to be human in order to pay the penalty for humans. Second, this verse says that because Jesus is human like us, He is able to be a merciful and faithful high priest. His humanity enables Him to more fully sympathize with us and identify with us. I cannot help but believe that it is very destructive to our comfort and faith to not know that Jesus is still man and in His body. For if He is not still man in heaven, how could we have comfort knowing that He can fully sympathize with us? He can sympathize and be a faithful high priest and know what we are going through not just because He was once on earth as a man, but because He continues forever as that same man.
Each nature remains distinct
The truths of Christ's two natures full manhood and full Godhood are pretty well understood and known by Christians. But for a right understanding of the Incarnation we must go even further. We must understand that the two natures of Christ remain distinct and retain their own properties. What does this mean? Two things: (1) They do not alter one another's essential properties, and (2) neither do they mix together into a mysterious third kind of nature.
First, it would be wrong to think that Christ's two natures mix together to form a third kind of nature. This is one of the heresies that the early church had to fight. This heresy taught that "the human nature of Christ was taken up and absorbed into the divine nature, so that both natures were changed somewhat and a third kind of nature resulted. An analogy to [this] can be seen if we put a drop of ink in a glass of water: the mixture resulting is neither pure ink nor pure water, but some kind of third substance, a mixture of the two in which both the ink and the water are changed. Similarly, [this view] taught that Jesus was a mixture of divine and human elements in which both were somewhat modified to form one new nature."5 This view is unbiblical because it demolishes both Christ's deity and humanity. For if Christ's two natures mixed together, then He is no longer truly and fully God and truly and fully man, but is some entirely different kind of being that resulted from a mixture of the two natures.
Second, even if we acknowledge that the natures do not mix together into a third kind of nature, it would also be wrong to think that the two natures changed one another. For example, it would be wrong to conclude that Jesus' human nature became divine in some ways, or that His divine nature became human in some ways. Rather, each nature remains distinct, and thereby retains its own individual properties and does not change. As the council of Chalcedon stated it, "...the distinction of natures being by no means taken away by the union, but rather the property of each nature being preserved..."6 Jesus' human nature is human, and human only. His divine nature is divine, and divine only. For example, Jesus' human nature did not become all knowing through its union with God the Son, and neither did His divine nature become ignorant of anything. If any of the natures underwent a change in its essential nature, then Christ is no longer truly and fully human, or truly and fully divine.
Christ is only one Person
What we have seen so far about the deity and humanity of Christ shows us that Christ has two natures -- a divine nature and a human nature -- , that each nature is full and complete, that they remain distinct and do not mix together to form a third kind of nature, and that Christ will be both God and man forever.
But if Christ has two natures, does this mean that He is also two people? No, it does not. Christ remains one person. There is only one Christ. The church has historically stated this truth in this way: Christ is two natures united in one person forever.
At this point we find another heretical view to beware of. This view, while acknowledging that Jesus is fully God and fully man, denies that He is only one Person. According to this view, there are two separate persons in Christ as well as two natures. In contrast to this, the Bible is very clear that, while Jesus has two natures, He is only one Person. In other words, what this means is that there are not two Jesus Christ's. In spite of the fact that He has a duality of natures, He is not two Christs, but One. While remaining distinct, the two natures are united together in such a way so as to be one Person.
To put it simply, there is a certain sense in which Christ is two, and a different sense in which Christ is one. He is two in that He has two real, full natures one divine and one human. He is one in that, while remaining distinct, these two natures exist together in such a way as that they constitute "one thing." In other words, the two natures are both the same Jesus, and thus are one Person. As the Chalcedonean creed says, Christ is "to be acknowledged in two natures...concurring in one Person and one Subsistence, not parted or divided into two persons, but one and the same Son, and only begotten, God, the Word, the Lord Jesus Christ..."
Evidence that Christ is Only One Person
We will look at three pieces of the biblical teaching that while Christ has two distinct and unchanged, He nonetheless remains one Person.
1. Both natures are represented in Scripture as constituting "one thing," that is, as united in one Person. We read in John 1:14, "And the word became flesh and dwelt among us." Here we see the two natures: the Word (His deity) and flesh (humanity). Yet we also see that there is one Person, for we read that the Word became flesh. "Became" requires that we acknowledge a unity of the two natures such that they are one thing--that is, one Person. For in what sense could John write that the word became flesh if they do not constitute one Person? It surely cannot mean "turned into" flesh, for that is against the Scriptural teaching on the distinctness of the natures. Additional Scriptures relating to this line of evidence are Romans 8:3, Galatians 4:4, 1 Timothy 3:16, Hebrews 2:11-14, 1 John 4:2,3.
2. Jesus never speaks of Himself as "We," but always as "I"
3. Many passages refer to both natures of Christ, but it is clear that only one person is intended It is impossible to read the following passages, which clearly affirm Christ's two natures, and yet conclude that Christ is two Persons. "For what the Law could not do, weak as it was through the flesh, God did: sending His own Son in the likeness of sinful flesh and as an offering for sin, He condemned sin in the flesh..." (Romans 8:3). "But when the fulness of the time came, God sent forth His Son, born of a woman, born under the law..." (Galatians 4:4). "...who, although He existed in the form of God, did not regard equality with God a thing to be grasped [that is, exploited to His own advantage], but emptied Himself, taking the form of a bond-servant, and being made in the likeness of men" (Philippians 2:6-7).
Having seen that Christ is two natures in one person, and having also seen what is involved in this, we will now examine one of the major implications of this, which should help us to complete the picture and our understanding.
Implication: Things that are true of one nature but not the other are nonetheless true of the Person of Christ
As we have seen earlier, the fact that Christ is two natures means that there are things that are true of His human nature that are not true of His divine nature. And there are things true of His divine nature that are not true of His human nature. For example, His human nature hungered, but His divine nature could never be hungry. So when Christ hungered on earth, it was His humanity that hungered, not His divine nature.
But the truth that we are now in a position to understand, is that by virtue of the union of the natures in one Person, the things that are true of and done by only one of Christ's natures, are nonetheless true of and done by the Person of Christ. In other words, things which only one nature does can be considered to have been done by Christ Himself. Likewise, things that are true of one nature but not the other are true of the Person of Christ as a whole. What this means, in simple terms, is that if there is something that only one of Christ's natures did, He can still say, "I did it."
We have many instances in Scripture which demonstrate this. For example, Jesus says in John 8:58, "...before Abraham was born, I am." Now, Christ's human nature did not exist before Abraham. It is Christ's divine nature that eternally exists before Abraham. But since Christ is one Person, He could say that before Abraham was, He is.
Another example is Christ's death. God cannot die. We should never speak of Christ's death as the death of God. But humans can die, and Jesus' human nature did die. Thus, even though Jesus' divine nature did not die, we can still say that the Person of Christ experienced death because of the union of the two natures in the one Person of Christ. Because of this, Grudem says, "by virtue of union with Jesus' human nature, his divine nature somehow tasted something of what it was like to go through death. The person of Christ experienced death."7
Have you ever wondered how Jesus could say that He did not know the day or hour of His return (Matthew 24:36) even though He is omniscient (John 21:17). If Jesus is God, why didn't He know the day of His return? This is solved by our understanding that Christ is one Person with two natures. The answer is that in regards to His human nature, Jesus does not have all knowledge. Thus, in His human nature He really did not know the day or hour of His return. But in His divine nature, He does have all knowledge and thus in His divine nature He did know when He would return.
Here comes the most fascinating part. Since the two natures are united in one Person, the fact that Christ's human nature didn't know when He would return means that the Person of Christ did not know when He would return. Thus, Jesus the Person could truly say, "But of that day and hour no one knows, not even the angels of heaven, nor the Son, but the Father alone" (Matthew 24:36). At the same time, by virtue of His divine nature, we can also say that the Person of Christ did know when He would return. Knowledge and ignorance of the time of His return are both true of the Christ, but in different ways. In His human nature, the Person of Christ was ignorant of when He would return. In His divine nature, the Person of Christ did know when He would return. Thus, Christ Himself both knew and did not know when He would return.
We have seen the biblical evidence for the fact that Christ is God the Son, He has both a divine and human nature, that each nature is full and complete, that each nature remains distinct, that Christ is nonetheless one Person, and that things which are true of one nature are true of the Person.
The relevance of these truths to us should go without saying. For they go to the very heart of who Christ is. Knowing these truths will greatly affect the way you view Christ and will make the gospel accounts of His life come more alive. As such, this understanding will deepen our devotion to Christ.
Second, having this richer understanding of the Incarnation of God the Son should greatly enhance our worship. We will have great marvel and gladness at the fact that the eternal Person of God the Son became man forever. Our recognition of Christ's worth will be heightened. And our faith in Him will be strengthened by having this deeper understanding of who He is.
The union of Christ's deity and humanity in one Person makes it such that we have all that we need in the same Savior. How glorious. Because Jesus is God, He is all-powerful and He cannot be defeated. Because He is God, He is the only adequate Savior. Because He is God, believers are safe and can never perish; we have security. Because He is God, we can have confidence that He will empower us for the task that He commands us for. And because He is God, all people will be accountable to Him when He returns to judge the world.
Because Jesus is man, He has experienced the same things that we do. Because He is man, He can identify with us more intimately. Because He is man, He can come to our aid as our sympathetic High Priest when we reach the limits of our human weaknesses. Because He is man, we can relate to Him--He is not far off and uninvolved. Because He is man, we cannot complain that God does not know what we are going through. He experienced it first-hand.
Finally, we need to be ready to defend the truth of Jesus' deity, Jesus' humanity, and their joining inconfusedly in one Person . Therefore, consider committing to memory many of the verses which teach that Jesus is both God and man, and be able to explain the relationship between Christ's two natures to others.
May we look forward to the day when we see Him face to face, and until then may the joyful hope of this day inspire in us a great diligence in serving and worshiping Him.
1 J.I. Packer, Knowing God (Downers Grove, Illinois: InterVarsity Press, 1993 edition), p. 53.
2 Wayne Grudem, Systematic Theology: An Introduction to Biblical Doctrine (InterVarsity and Zondervan Publishing, 1994), p. 556.
3 Packer, p. 57.
4 Grudem, p. 554.
5 Grudem, p. 556.
6 Chalcedonean Creed, quoted in Grudem, p. 557.
7 Grudem, p. 560.