"Surely," Isaiah tells us, "Surely he has borne our griefs and carried our sorrows" (53:4); and again: "the Lord has laid on him the iniquity of us all" (53:6); and again: "he bore the sin of many" (53:12). It's easy to misunderstand this. If we're not careful, we can think that what's happening in the passion is that God is simply punishing an innocent victim for our wrongdoings - as if God simply requires that the punishment for our crimes should be enacted, and it doesn't matter who is punished. But Jesus is not just a mute sacrificial animal. If he is like a lamb led to the slaughter, it's not because God is victimizing him; it is because he is God himself fulfilling his own purpose; it is because he is God the Son, freely and lovingly acting out the will of the Father. "It was the will of the Lord to crush him" (53:10). That does not mean that God just vented his anger at sin on Jesus. It means that he, Jesus, the Son of God, is God himself bearing the wounds of our wickedness. God does not save us by sacrificing someone other than himself. God sacrifices himself. In his Son, God himself, bears our sins. He makes himself an offering for sin (Hebrews 7:27). Or as Colossians puts it, "in him" - Jesus - "all the fullness of God was pleased to dwell, and through him to reconcile to himself all things, whether on earth or in heaven, making peace by the blood of his cross" (1:19).
"How does this change the course of human life? In this way: By becoming one of us, by absorbing into himself the full extent of our sin, God destroys sin. God sets aside a whole world, the world we have made for ourselves, and God puts in its place a new world, the world of the new creation. In that world, we are set free from sin, and set free to live in fellowship with God. Good Friday, and its final outworking on Easter Day, is the new creation, the re-creation of the world. It's the point at which the world and all humankind are made new. We can't do this; we can't undo the knot we have tied. But God can: God has power and authority to make new, and in the passion of his Son performs this ultimate act of mercy, bearing our iniquities and so setting us free. And for us, this means that we become righteous. That is, we are put back in relation to God. Fellowship, friendship with God, is restored - not by us, but by God himself. We no longer turn to our own way; God himself turns us back to himself.
- from the sermon, The Triumph of Divine Resolve (Is. 53:6, 10), in Confronted by Grace, p. 85-86