The greatest problem in the world is sin. Yet as David cried out in Psalm 51, "Wash me thoroughly from my iniquity, and cleanse me from my sin!" and so also do we need the precious blood of Christ that alone can forgive all of our sin. As the hymns say, "Wash me, Savior, or I die..." and "The vilest offender who truly believes, that moment from Jesus a pardon receives."