Dennis Prager told a great story about this yesterday. To summarize:
A man slandered and told lies about a rabbi. He then went to the rabbi and begged for forgiveness.
Man: Rabbi, can you forgive me?
Rabbi: Yes, but first you must do something. Bring me three feather pillows.
Man: brings 3 pillows. Now will you forgive me?
Rabbi: Not yet. Cut the pillows open.
Man: cuts the pillows open. Now can you forgive me?
Rabbi: Not yet. Go outside and throw the pillows into the air.
Man: does as required. Now can you forgive me, Rabbi?
Rabbi: Not yet. You must go outside and bring me all the feathers