In the Old Testament, the sacrifice was an animal. Whenever an animal was slain, everybody laid hands on the animal, and that way the sins were passed to the animal, and then the animal was slain. It was very clear to everybody in the Old Testament time that the animal was being slain in their place as the atonement, as the way of paying the price necessary for ‘at-one-ment.’

The poor Old Testament people wondered, ‘Why in the world is this ram, is this dead lamb, is this dead bullock, how in the world is this being our sacrifice? How is this being our substitute?’ Of course the New Testament answer is it was just a picture of the real substitute, who is Jesus Christ. Jesus was the sacrifice. This is very basic. You will not understand the love of God unless you see that what he did was to be a substitutionary sacrifice.

There are many, many churches that hate the idea of a God who needs payment. They hate the idea of Jesus Christ having to come and take the wrath of God, to be an atoning sacrifice. My friends, suppose you deny the idea that you’re so wicked that Jesus Christ had to come and pay the atoning sacrifice to reconcile us. If you deny that, you have evacuated the cross of all of its eternal and endless profundities. You have made it something senseless…

Unless you believe you are lost unless Jesus died for you, unless you believe you’re a sinner, unless you believe you would be lost except Jesus died for you, the cross makes no sense. You have evacuated it of all meaning and you cannot understand the love. The love of Jesus Christ dying for us is the thing that’s supposed to move us to walk in love. What else would move you to walk in love? It was a sacrifice.

– Tim Keller

Words found in Tim Keller’s 1991 Sermon, “The Sweetness of the Cross”