“The idea is not simply that we have been forgiven, and therefore ought to forgive, but that God Himself, in Christ, has forgiven us, and therefore our debt is incalculable. No matter how much wretched evil has been done against us, it is little compared with the offense we have thrown in the face of God. Yet God in Christ has forgiven us. If we know anything of the release of this forgiveness, if we have glimpsed anything of the magnitude of the debt we owe to God, our forgiveness of others will not seem to be such a large leap.”
–D.A. Carson, Love in Hard Places (Wheaton, IL: Crossway, 2002), 80-1.