Jesus is called the Son of God and Son of Man because He is both human and divine. He is revealed in Scripture as God the Son come in the flesh (John 1). These truths are absolute essential to Christianity. Denial of any of either His humanity or Deity is regarded as a heretical and our salvation questionable. Scripture backs this up when John writes, “By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God, and every spirit that does not confess Jesus is not from God” (1 John 4:2-3). When looking at the Deity and Humanity of Jesus, it is important to investigate the primary source material. In this case it would be Scripture.
Scripture gives evidence of His Deity when the high priest accused Jesus of being the Messiah, the Son of God (Matt. 26:63). Jesus reply was a clear indication of His deity, “You have said so. But I say to all of you: From now on you will see the Son of Man sitting at the right hand of the Mighty One and coming on the clouds of heaven” (Matt. 26:64). His disciples also recognized His deity when they responded to Him by saying, “My Lord and my God” (John 20:28). There is additional evidence in Scripture that point to His deity which I encourage you to further read and study.
Concerning the humanity of Christ, Scripture tells us that Jesus was fully human. He experienced the same physical limitations as other human beings such as hunger, thirst and fatigue. One of the scriptures that speak to his physical human nature is found in Luke 2:52. Jesus growing in “wisdom and statue, and in favor with God and man.” There are many scriptures in the bible that speak to Jesus being fully man and I implore you to study and read them.
There is nothing more central to the Christian faith than knowing who Jesus is. The knowledge of who He is not only brings about new life but also worshipful relationship toward God. Our faith as evangelical Christians rests upon the knowledge of who Christ is both in His Deity and Humanity. If what Christ accomplished on the cross is to avail for man, then it must be the work of the human Jesus. But if the work on the cross is to atone for all mankind then it must be the work of the divine Christ. Understanding who Jesus is, gives us a fuller picture of the work He performed. Most importantly, it draws us closer in a relationship with Jesus Christ.