It no doubt seems strange to us today to talk about a human being as also being God, and yet that is what we celebrate at Christmas time. We must also remember that this might not have seemed strange to the people of Jesus’ time and day. They believed that human beings were gods or became gods or were appearances of the gods (see Acts 14:8–20 for an example).
The problem for the early Christians was that they believed that there was only one God, so Jesus could not be a sort of lesser god that appeared in human form. The early Christians emphatically rejected that possibility at the Council of Nicaea in A.D. 325. Its conclusion was that Jesus was “begotten from the Father before all ages, God from God, Light from Light, true God from true God, begotten, not made; of the same essence as the Father.”
One possibility, then, was that Jesus was the appearance of God in a different role, just as I am a son, a father, and a brother. The problem is that the Bible clearly presented Jesus as interacting with the Father as another person and as sending the Spirit as another person. So, they rejected the idea that there was only one person in God. In the words of the ancient Athanasian Creed, “we worship one God in trinity and the trinity in unity, neither blending their persons nor dividing their essence. For the person of the Father is a distinct person, the person of the Son is another, and that of the Holy Spirit still another. But the divinity of the Father, Son, and Holy Spirit is one, their glory equal, their majesty coeternal.”
With that cleared up, the question became: how are the human and divine united in Jesus? One possibility was that there were two persons in Jesus. The trouble with this is that the Bible clearly teaches that the eternal Son of God became a human being. Jesus is a “He” not a “they.” So, there is one person in Jesus, the second person of the Trinity.
By the end of the 4th century, there was little dispute that Jesus had a divine nature, but what about his human nature? Was it a real human nature? Did it become a sort of mixture of divine and human when Jesus became incarnate in the womb of the Virgin Mary?
The early Christians saw that it was necessary that Jesus be a real human in order to represent us, sympathize with us, and carry out our salvation. They also knew that Jesus had ate, slept, wept, walked, and talked as a real human being. So, they insisted that Jesus had a real and full human nature, body and soul.
At the Council of Chalcedon in A.D. 451, the leaders of the church adopted this explanation of the incarnation as capturing the fullness of the biblical testimony. Jesus was “recognized in two natures, without confusion, without change, without division, without separation; the distinction of natures being in no way annulled by the union, but rather the characteristics of each nature being preserved and coming together to form one person and subsistence, not as parted or separated into two persons, but one and the same Son and Only-begotten God the Word, Lord Jesus Christ.”
The Church gradually gained clarity on the truths we confess today that Jesus Christ is the second person of the Trinity, the eternal Son of God, who became a real human being in order to bring us to eternal salvation.
What is the significance of all this? Charles Hodge says it well in his Systematic Theology:
Although the divine nature is immutable and impassible, and therefore neither the obedience nor the suffering of Christ was the obedience or suffering of the divine nature, yet they were none the less the obedience and suffering of a divine person. The soul of man cannot be wounded or burnt, but when the body is injured it is the man who suffers. In like manner the obedience of Christ was the righteousness of God, and the blood of Christ was the blood of God. It is to this fact that the infinite merit and efficiency of his work are due. This is distinctly asserted in the Scriptures. It is impossible, says the Apostle, that the blood of bulls and of goats could take away sin. It was because Christ was possessed of an eternal Spirit that He by the one offering of Himself hath perfected forever them who are sanctified. This is the reason given why the sacrifice of Christ need never be repeated, and why it is infinitely more efficacious than those of the old dispensation. This truth has been graven on the hearts of believers in all ages. Every such believer says from his heart, “Jesus, my God, thy blood alone has power sufficient to atone.”
Martin Luther explains the same point from a slightly different angle:
We Christians must know that if God is not also in the balance and gives the weight, we sink to the bottom with our scale. By this I mean: If it were not to be said, God has died for us, but only a man, we should be lost. But if “God’s death” and “God died” lie in the scale of the balance, then He sinks down, and we rise up as a light, empty scale. But, indeed, He can also rise again or leap out of the scale; yet He could not sit in the scale unless He became a man like us.
The point is that Christ’s humanity enables Him to take our place and suffer in our place and His divinity gives Him the power and merit to overcome what our sin deserved.
When properly understood, the implications of Jesus’ incarnation are wonderful beyond compare. It calls us to understand that God wants to connect with us. It also warns us that our sin and separation from God is no small problem, since it required the God-man to solve it. But it also assures us that since the God-man is the solution to our problem, then the solution is complete. We have a full and complete restoration and salvation that we merely need to receive by faith.