The Enemy allows disappointment to occur on the threshold of every human endeavor. It occurs when the boy who was enchanted in the nursery by 'Stories from the Odyssey' buckles down to really learning Greek. It occurs when lovers have gotten married and begun the real task of learning to live together. In every department of life it marks the transition from dreaming aspiration to laborious doing. The Enemy takes this risk because He has a curious fantasy of making all these curious little human vermin into what He calls His 'free' lovers and servants---'sons' is the word He uses with His inveterate love of degrading the whole spiritual world by unnatural liaisons with the two-legged animals. Desiring their freedom, He therefore refuses to carry them, by their mere affections and habits, to any of the goals He sets before them: He leaves them to 'do it on their own.' And there lies our opportunity. But also remember, there lies our danger. If once they get through this initial dryness successfully they become much less dependent on emotion and thus much harder to tempt.
------C. S. Lewis, The Screwtape Letters
(from Redeemer Presbyterian Church recent Sunday program)