True Sorrow for Our Sins

“Deep sorrow does not come because one has violated a law, but only if one knows he has broken off the relationship with Divine Love. But there is yet another element required for regeneration, the element of repentance and reparation. Repentance is a rather dry-eyed affair; tears flow in sorrow, but sweat pours out in repentance. It is not enough to tell God we are sorry and then forget all about it. If we broke a neighbor's window, we would not only apologize but also would go to the trouble of putting in a new pane. Since all sin disturbs the equilibrium and balance of justice and love, there must be a restoration involving toil and effort. To see why this must be, suppose that every time a person did wrong he was told to drive a nail into the wall of his living room and every time that he was forgiven he was told to pull it out. The holes would still remain after the forgiveness. Thus every sin after being forgiven leaves “holes” or “wounds” in our human nature, and the filling up of these holes is done by penance, a thief who steals a watch can be forgiven for the theft, but only if he returns the watch.”

― Fulton J. Sheen, Peace of Soul: 

Timeless Wisdom on Finding Serenity and Joy by the Century's Most Acclaimed Catholic Bishop