Piper on Forgiveness:

The biblical motive for being a forgiving person may be deeper than being forgiven. It is true to say: The motive for being a forgiving person is that we have been forgiven by God when we did not deserve it (Ephesians 4:32). The bottom of this motive is not God’s forgiveness, but what God’s forgiveness gives. It gives us God. … God is the goal of forgiveness. He is also the ground and means of forgiveness. It comes from him; it was accomplished through his Son; and it leads people back to him with their sins cast into the deepest sea. Therefore the motive for being a forgiving person is the joy of being freely and joyfully at home with God.   – Don’t Waste Your Life, John Piper