The divinity of Jesus is and has been from the beginning a core component of the Christian faith. There are several reasons why Christians have always affirmed and indeed must affirm the deity of Christ. First, Scripture itself clearly testifies to the fully deity of Jesus as the Son of God. To name just a few:

• the Incarnation passage in John
• Thomas’ outburst of faith, “My lord and my God!” to Jesus upon his resurrection
• Thomas’ outburst of faith, “My lord and my God!” to Jesus upon his resurrection
• the quotes throughout the New Testament but especially in Hebrews where God is quoted as addressing Jesus as God
• the quotes throughout the New Testament but especially in Hebrews where God is quoted as addressing Jesus as God
• the obvious reality that the early church prayed to and worshipped Jesus

So the Christian is first of all obliged by the Scriptures to acknowledge Jesus as God. Beyond this, however, is the reason that it had to be God Incarnate who saved human beings and not merely another human being (still less any other created thing). First, salvation entails reconciliation between God and humanity. That is, the salvation Christ accomplished was not only between God and human beings as individuals, but between God and human nature which was broken in the fall and separated from God in whose image it was made. That Christ is the image of the invisible God (Colossians 1:15, Hebrews 1:3) is not only an affirmation of the nature of the divine Son but an affirmation of the restored humanity of Jesus the Messiah.

Second, Jesus was a substitution for human sins. For this he of course had to be a human being (as the author of Hebrews notes: the blood of sheep and goats could not make purification for human sins). However, he had also to be God. Even if one mere human lived a perfectly sinless life, this perfect life would not be transferrable to another human being: it would be his alone, and would have no extra righteousness to give to another. But Jesus is fully God, and has all righteousness. Indeed, it is the righteousness of God—infinite, boundless, untainted by sin—that Christians receive by faith. It is not one man’s righteousness somehow wafted across a courtroom (to borrow N. T. Wright’s metaphor), but the righteousness of God in which humans participate because they are united with Christ.

Finally, Jesus came to overcome death. To die, he had to be a man, but to bring life he had to be God. Human beings do not have in themselves the power of life (still less to overcome death)—but God whose very name is “I AM”/“HE IS” has life in himself. Jesus the divine Son had and has life in himself, and he therefore can and did overcome death. In his restored humanity, death no longer has any power. His resurrection was the first moment when this divine power of life broke into the fallen reality and gave a formerly mortal human body immortality. Believers have in one sense already died and been raised in him, and in another sense look forward to a fuller participation in that divine reality of life that does not end. Death died in the resurrection because Christ was not merely a man, because his return from the grave was not like Lazarus’ a mere rescuscitation but the triumph of divine life over human frailty.