At the incarnation we see God become man. Jesus Christ, the second person of the trinity, took upon himself human flesh. In doing so, he didn’t cease to be fully God nor did he become something more than man (either a demi-God or a super-human). Jesus became the God-Man; fully human and yet fully God with two separate natures united in one person.
If you think that sounds weird, that fact isn’t lost on Christians. Jim Packer said, ‘Nothing in fiction is so fantastic as is this truth of the incarnation.’ He goes on, ‘This is the real stumbling block in Christianity. It is here that Jews, Muslims, Unitarians, Jehovah’s Witnesses, and many of those who feel the difficulties concerning the virgin birth, the miracles, the atonement, and the resurrection have come to grief.’ But it is, he insists, ‘in itself an unfathomable mystery, but it makes sense of everything else that the New Testament contains.’
I am not going to spend any time today defending the Incarnation. I am simply going to assume it as the evident teaching of scripture. Jesus Christ is, according to the Bible, both fully God and fully man. What I want to do here is dig into why that in any way matters. Today, I will focus on his humanity and tomorrow his divinity. So, why is Jesus’ full humanity so important?
A suitable representative
Way back in Eden, Adam – the first man – served as the representative for all humanity. As our federal head, Adam’s sin meant we all sinned and Adam’s guilt is imputed to us and becomes our guilt. Much of the rest of the Old Testament is concerned with trying to find a second Adam who would obey God and become the faithful covenant partner through whom God could save his people. If all were guilty in Adam, we need a representative through whom all could be made righteous. Though many potential second Adams rise up but ultimately fail, the Bible is clear that Jesus is sent by God as this faithful representative. As such, Jesus had to be a man – made just like us – so that he could be an appropriate and adequate representative for the human race.
To be a substitutionary sacrifice
The Bible is very clear that without the shedding of blood there is no forgiveness of sin (Lev 17:11 cf. Heb 9:22). That is what the Old Covenant sacrificial system pointed toward. Animals could not meaningfully pay for sin; it was a picture to God’s people of how God would eventually, fully and finally, deal with the problem of sin.
For this reason, Jesus had to become a man. First, because God cannot die. If God cannot die, it causes something of a problem with him being the sacrifice for sin. But the man Christ Jesus can die and so is able to be the substitutionary atonement for mankind.
Equally, Hebrews 2:17 says, ‘he had to be like his brothers and sisters in every way, so that he could become a merciful and faithful high priest in matters pertaining to God, to make atonement for the sins of the people.’ In other words, Jesus had to be fully human in order to make atonement for the sins of the people. He had to be like us in order to be an acceptable substitute for us.
To be a suitable mediator
Look back at Hebrews 2:17 again. The writer goes on, ‘For since he himself has suffered when he was tempted, he is able to help those who are tempted.’ The Bible is clear that God cannot be tempted, just as it is clear that God cannot die. But it tells us that Jesus was tempted and did die. For some, that proves he was not fully God (more on which tomorrow). But, in truth, it simply proves that Jesus was fully human and not only God.
Nevertheless, Jesus came to mediate between man and God. In any mediation, the mediator has to be acceptable to both parties. If Jesus was going to represent the human race, he had to be like the human race. If Jesus is going to mediate on behalf of humanity to God, he needs to actually understand what it is like to be human. if Jesus were not fully human, we would not be able to mediate effectively or appropriately on our behalf because he would not be like us nor know what it is like being us. But as it is, Jesus became one of us so that he could mediate on our behalf and can sympathise with us in our weakness.
To bring us proper hope
One point the Apostle Paul makes about the Christian faith concerns the resurrection of Jesus. Specifically, if Jesus hasn’t been raised, none of us will be raised (cf. 1 Cor 15). Repeatedly the New Testament points to Jesus having gone first, or being the firstfruits, of the resurrection. That is to say, we can have hope of a future resurrection because Jesus was resurrected first.
Of course, if Jesus is not fully man, that argument loses all its power. If Jesus was simply raised because he is God, what hope does that give the rest of us who very much are not God nor are we little gods. If Jesus is not fully human, his resurrection provides no real hope for humanity. But if God has raised the man Christ Jesus – the new and better Adam (which literally means man) – who has been faithful on our behalf as our representative, then the claim to a future hope of resurrection suddenly has power. God did not simply raise God because God cannot die and God could raise himself from the dead. Rather, he raised the man Christ Jesus who – being just like us and functioning as the substitutionary representative for humanity – gives us real hope that because he lives we will live too and because he has been raised we shall be raised with him.