Luke 19:8
And Zacchaeus stood and said to the Lord, "Behold, Lord, the half of my goods I give to the poor; and if I have defrauded any one of anything, I restore it fourfold." And Jesus said to him, "Today salvation has come to this house, since he also is a son of Abraham."
Somehow some Christians have the notion that "penance" is the attempt to earn the forgiveness of God. Some actually claim that the need for penance in the sacrament of reconciliation is a system of "works salvation" condemned by God. Yet Jesus doesn't look terribly displeased with Zacchaeus when he does an act of penance after repenting his sins as a squeezing, wrenching, grasping, scraping, clutching, covetous old sinner. Instead, Jesus seems to be under the distinct impression that it is only common sense that a sinner who repents his sins will do something to amend the damage, and that this is what anybody who has had love rekindled in his heart would want to do. The Church thinks the same thing and so insists that reconciliation needs to be incarnate in our actions by some act of penance. Just as the Word became flesh, so our love must become flesh.