In our members there is a slumbering inclination toward desire, which is both sudden and fierce. With irresistible power desire seizes master over the flesh. All at once a secret, smouldering fire is kindled. The flesh burns and is in flames. It makes no difference whether it is sexual desire, or ambition, or vanity, or desire for revenge, or love of fame and power, or greed for money . . . Joy in God is in course of being extinguished in us as we seek all our joy in the creature. At this moment God is quite unreal to us, he loses all reality, and only desire for the creature is real . . . Satan does not here fill us with hatred of God, but with forgetfulness of God . . . The powers of clear discrimination and of decision are taken from us. The questions present themselves: “Is what the flesh desires really sin in this case?” “Is it really not permitted to me, yes – expected of me, now, here, in my particular situation, to appease desire?” . . . It is here that everything within me rises up against the Word of God. Powers of the body, the mind and the will, which were held in obedience under the discipline of the Word, of which I believed that I was the master, make it clear to me that I am by no means master of them. . . The adversary deploys my powers against me.
--Dietrich Bonhoeffer, Creation and Fall & Temptation: Two Biblical Studies (New York, NY: Touchstone, 1997) p. 132.