Jesus was innocent and lived a perfect sinless life, but He was crucified anyway. Sounds harsh doesn’t it? It was the plan of God though, carried out by men. God says that the penalty for sin is death. This is why, in the Old Testament, you see God instructing the Israelites to sacrifice a lamb once a year for the forgiveness of their sins. The lamb died in their place. But that was a temporary forgiveness. They had to do this each year.
Jesus came to take the penalty for humanity’s sin, for our sin, once and for all, in our place. Rather than us die and be permanently, eternally separated from God, Jesus paid for our sin on the cross, in order that we could be forever forgiven and have eternal life. As the perfect man He traded His life to satisfy God’s justice against all of mankind’s sin. This is exactly why Jesus came, as our Saviour, to save us from God's judgment, condemnation and payment of our sin. While hanging on the cross, Jesus was aware of any sin we have ever committed, or ever will commit in the future. Jesus took the punishment for our sins for us.