The Fool and His Foolishness

How does this man whose name means 'fool' an example of all of our depraved nature of the flesh? How is David a type of Christ? How is free-will really just evil foolishness that every person is born in? Does the mercies of the LORD indicate if a person is a vessel of wrath or mercy? How is the real issue in this passage the rebellion against the LORD in that they would not have the LORD's anointed to reign over them? Has there ever been an innocent person?