Over the course of church history, every heresy finds its end in one of two places: the person of Jesus (as God and Man) or the Trinity. A truly historic, orthodox faith holds to both Jesus being fully God and fully Man and a Trinitarian God who is one yet three: Father, Son, and Spirit.
In two brief posts, I want to address these two doctrines. My goal is simply to summarize why Jesus must be God and why God must be Trinitarian. Let’s start with Jesus. Why must Jesus be God?
If Jesus is not God, then he cannot die in our place on the cross. It simply boils down to this. There can be no substitutionary atonement if the substitute has to pay for his own sins. Jesus must be God because only God can satisfy his own wrath and pay the wages of sin (death). No mere human could. Yet at the same time, Jesus must be human because only a human deserves to die, for humans are the ones who have sinned against God.
If Jesus were not God, he would be another sinner (by definition) dying for sinners. Thus his death on the cross would be a wonderful example of love, but all it would be is an example! It would not be efficacious (i.e. it couldn’t produce the desired result, namely the redemption of sinners). Christ’s death would be stripped of any working power. It would be a great lesson in how we should live our lives. But that would actually not be loving, because it would crush us. No one can live up to that example (at least not me)! And what is it if a mere sinner dies for another sinner? Nothing. But this is not the essence of the gospel story. The essence of the gospel, indeed the whole Bible, is that everything in this world (including the world itself) is so messed up because of sin that only God himself can redeem you, me, and the whole cosmos. God himself must do for us what we could not do for ourselves.
That’s what we get when we meet Jesus. This is why Jesus must be God.
Scriptures to consider: Genesis 3:1-24 (esp. v. 15); John 1:1-18; 10:22-42; Colossians 1:15-23; Hebrews 1:1-14; 7:11-28