“Niebuhr’s reflections on the contemporary meaning of the Christian concept of original sin taught liberals and everyone else about “the mixed and ambivalent character of human nature — creative impulses matched by destructive impulses, regard for others overruled by excessive self-regard, the will to power, the individual under constant temptation to play God to history.” The Easter and Passover stories underscore the dual nature of our history: sin and bondage; redemption and liberation.”