1) Isaiah prophesied that God would slay Leviathan and the master of the sea, symbolic references to defeating Assyria, Egypt, and Satan. 2) Jesus defeated Satan during his temptation in the desert, drawing on prophecies where he would be called Wonderful Counselor, Mighty God, Everlasting Father, and Prince of Peace. 3) The Old Testament contained the first gospel, foretelling Jesus's crucifixion, vicarious suffering, and role as the cut-off Messiah, which are applied through confessing sin, forsaking it, and turning to God.