Our Scripture reading today is Luke 6:36, "Be ye therefore merciful, as your  Father also is merciful."
 
God's mercy can be defined as not getting what we deserve.  All of mankind deserves to spend eternity in the Lake of Fire.  The wages of our sin is the first and second death. (Romans 6:23 and Revelation 20:14)  God provided His Son, Jesus Christ, to be the sacrifice for our second death.  He is the propitiation for our sin.  This is mercy!
 
Once we experience the mercy of God, we ought to be willing to show mercy to others.  It isn't necessary that we get even with someone when they offend us.  We should offer them mercy just as God offered mercy to us.  Just as His mercy never runs out neither should ours.