This is the heart of the gospel–substitution. God made Him to be sin for us who knew no sin that we might be reckoned the righteousness of God in Him. That’s the gospel. The gospel is not simply that God forgives sin, but that God forgives sin by imputing that sin to His own son and punishing it. He’s rejected for us, pierced for us, crushed for us. He has nowhere to lay His head for us. Cast out for us, suffers hell for us, undergoes the torment for the wicked and damned for us.