To trust in works, which one ought to do in fear, is equivalent to giving oneself the honor and taking it from God, to whom fear is due in connection with every work. But this is completely wrong, namely to please oneself, to enjoy oneself in one’s works, and to adore oneself as an idol.
Martin Luther, Luther’s Works, Vol. 31: Career of the Reformer I, ed. Jaroslav Jan Pelikan, Hilton C. Oswald, and Helmut T. Lehmann, vol. 31 (Philadelphia: Fortress Press, 1999), 46.