While this post is not meant to be an exhaustive discussion on the deity and humanity of Jesus, it will hopefully bring some clarity on how to understand the God-man. Wayne Grudem writes, “Jesus Christ was fully God and fully man in one person, and will be so forever” (529). There is a lot of meaning packed into that one, concise sentence. In the incarnation, Jesus was like us, and not like us at the same time. Likewise, in some ways we are like him and in other ways we are not. He was uniquely the God-man. No one existed that way before, and no one, other than Jesus, will exist that way again. Below we will unpack some of the basic principles and truths regarding the person of Jesus Christ.

Jesus’ Humanity

Jesus had a human body as seen in Luke 2:7 and 2:40. In his physical body he grew in understanding (Luke 2:52), got tired (John 4:6), got thirsty (John 19:28), and was hungry (Matt. 4:2). He also died a physical death on the cross (Luke 23:46), and resurrected in a physical body (Luke 24:39,42, John 20:17, 20, John 21:9,13). Grudem has this to say, “Jesus rose from the dead in a physical, human body, though one that was made perfect and was no longer subject to weakness, disease, or death” (532). Finally, Jesus ascended to Heaven in his perfect physical body (Acts 1:9, Luke 24:50-51). Jesus also had a human soul, comprised of mind, will and emotions. We’ve already seen, from the fact that Jesus “grew in wisdom,” that he had a human mind (Luke 2:52). This is also seen when Jesus says he doesn’t know when he will return to earth (Mark 13:32). Scripture again teaches that Jesus has human soul when it speaks of his emotions (John 12:27, John 13:21, Matt 26:38, Matt. 8:10, and John 11:35) and his will (Luke 22:42 and Mark 14:36).

Virgin Birth
Scripture clearly teaches the virgin birth. (Matt. 1:18-20, Luke 1:35)

This is important for several reasons. First and foremost, the virgin birth shows that salvation ultimately comes from the Lord. God brought it about by his power, not by any human endeavor. Secondly, the virgin birth made it possible to unite the full deity and full humanity in one person. If Jesus had taken on humanity as a fully grown adult, without having parents, and then descended from Heaven, it would be difficult to see him as fully human. On the other hand, if Jesus would have been born of two parents naturally and then had the divine nature miraculously united to his human nature, it would be difficult for us to understand his deity. While the virgin birth may seem at first glance to be an interesting way of doing things, this choice displays the perfect wisdom of God.

The Necessity of Jesus’ Humanity
Jesus was our representative and obeyed where Adam failed (Rom. 5:18-19, 1 Cor. 15:45-47). He was also our substitutionary sacrifice. If he had not been man, he could not have died in our place. If Jesus was not like us, the propitiation or sacrifice, would not have been an acceptable substitute ( Heb. 2:16-17). Furthermore, Jesus had to be human in order to be our mediator. Since we were alienated from God, we were in need of one who could represent us before God (1 Tim. 2:5).

Jesus’ Sinlessness 
First of all, God created us holy and we rebelled, and thus became sinful. However, Jesus did not rebel, so he remained holy and sinless. Scripture gives us these examples:
a. No one could actually show Jesus had sinned (John 8:46).
b. Jesus was without sin (Heb. 4:15).
c. Jesus was holy and blameless (Heb. 7:26).

Jesus Will Be Man Forever
Scripture teaches that Jesus kept his human nature after his resurrection (John 20:25-27). We also see that he ascended and will return the same way (Acts 1:11, 7:56, 9:5). Lastly, even though “the incarnation began in time, it continues forever” (Shedd, 623). Scripture confirms this (Rom. 9:5, Col. 2:9, Heb. 13:8, Eph. 2:6, Heb. 4:14-15). In other words, even though Jesus’ resurrected body was glorified, it was still human. Furthermore, after the resurrection, Jesus retained his human nature, and will do so forever. He will remain the God-man for eternity.

The Deity of Christ

First of all, Jesus is called God in both the Old and New Testament (Micah 5:2 & Is. 7:14, 9:6, John 1:1-3, John 1:14, 1 Cor. 1:16-17, Heb. 1:1, John 17:5,24, John 8:58).

Evidence That Jesus Possessed Attributes of Deity
We see many examples of Jesus’ omnipotence, for instance when he calmed the sea (Matt. 8:26-27) and multiplied the loaves and fish (Matt. 14:19). Jesus also made statements that clearly display his eternity. One of these statements is when Jesus said, “…before Abraham, I am” (John 8:58). He is called the Alpha and Omega (Rev. 22:13). Scripture also displays Jesus’ omniscience: Jesus knew people’s minds (Mark 2:8), He saw Nathaniel under the fig tree (John 1:48), and Peter affirmed that Jesus knew everything (John 21:17). Finally, Scripture declares that Jesus is worthy of worship (Phil 2:9-11, Heb. 1:6, Rev. 5: 12-13).

The Necessity of Jesus’ Deity
First, Jesus had to be fully God because salvation comes only from the Lord (Jonah 2:9). Also, just like with Jesus’ humanity, it is only if Jesus is fully God could he be a mediator between God and man (1 Tim. 2:5, John 14:9), otherwise he would not have been representative of both sides. Finally, only someone who is infinitely God could bear the weight of mankind’s sin.

Sources for this article:
Grudem, Wayne. Systematic Theology; An Introduction to Biblical Doctrine. Grand Rapids, MI: Zondervan, 2000.
Lewis, Kevin. Personal notes from Essential Christian Doctrine Lectures. Biola University; La Mirada, CA, 2013.
Shedd, William G.T. Dogmatic Theology. Phillipsburg, NJ: P&R Publishing, 2003.