Can you remember even just a little snippet of it? That would help. It seems to me that The Screwtape Letters is all about that....
...our aim is the absorption of its will into ours, the increase of our own area of selfhood at its expense. But the obedience which the Enemy demands of man is quite a different thing. One must face the fact that all the talk about His love for men, and His service being perfect freedom, is not (as one would gladly believe) mere propaganda, but an appalling truth. He really does want to fill the universe with a lot of loathsome little replicas of Himself – creatures whose life, on its miniature scale, will be qualitatively like his own, not because He has absorbed them but because their wills freely conform to His. We want cattle who can finally become food; He wants servants who can finally become sons.
~ C. S. Lewis, The Screwtape Letters
http://www.explorefaith.org/lewis/screwtape.html