“I do not think there is a demonstrative proof (like Euclid) of Christianity, nor of the existence of matter, nor of the good will and honesty of my best and oldest friends. I think all three are (except perhaps the second) far more probable than the alternatives. The case for Christianity in general is well given by Chesterton…As to why God doesn't make it demonstratively clear; are we sure that He is even interested in the kind of Theism which would be a compelled logical assent to a conclusive argument? Are we interested in it in personal matters? I demand from my friend trust in my good faith which is certain without demonstrative proof. It wouldn't be confidence at all if he waited for rigorous proof. Hang it all, the very fairy-tales embody the truth. Othello believed in Desdemona's innocence when it was proved: but that was too late. Lear believed in Cordelia's love when it was proved: but that was too late. 'His praise is lost who stays till all commend.' The magnanimity, the generosity which will trust on a reasonable probability, is required of us. But supposing one believed and was wrong after all? Why, then you would have paid the universe a compliment it doesn't deserve. Your error would even so be more interesting and important than the reality. And yet how could that be? How could an idiotic universe have produced creatures whose mere dreams are so much stronger, better, subtler than itself?”

“When two humans have lived together for many years it usually happens that each has tones of voice and expressions of face which are almost unendurably irritating to the other. Work on that. Bring fully into the consciousness of your patient that particular lift of his mother's eyebrows which he learned to dislike in the nursery, and let him think how much he dislikes it. Let him assume that she knows how annoying it is and does it to annoy - if you know your job he will not notice the immense improbability of the assumption. And, of course, never let him suspect that he has tones and looks which similarly annoy her. As he cannot see or hear himself, this easily managed.”

“[E]very time you make a choice you are turning the central part of you, the part of you that chooses, into something a little different than it was before. And taking your life as a whole, with all your innumerable choices, all your life long you are slowly turning this central thing into a heavenly creature or a hellish creature: either into a creature that is in harmony with God, and with other creatures, and with itself, or else into one that is in a state of war and hatred with God, and with its fellow creatures, and with itself. To be the one kind of creature is heaven: that is, it is joy and peace and knowledge and power. To be the other means madness, horror, idiocy, rage, impotence, and eternal loneliness. Each of us at each moment is progressing to the one state of the other.”

“He wants them to learn to walk and must therefore take away His hand.”

“My dear young lady,' said the professor...'there is one plan which no one has yet suggested and which is well worth trying.' 'What's that?' said Susan. 'We might all try minding our own business...”

“She looked at a silver birch: it would have a soft, showery voice and would look like a slender girl, with hair blown all about her face and fond of dancing. She looked at the oak: he would be a wizened, but hearty, old man with a frizzled beard and warts on his fact and hands, with hair growing out of the warts. She looked at the beech under which she was standing. Ah! --she would be the best of all. She would be a gracious goddess, smooth and stately, the Lady of the Wood.”

“Whenever you are fed up with life, start writing: ink is the great cure for all human ills, as I have found out long ago.”

“I write for the unlearned about things in which I am unlearned myself.”

“When things go wrong, you'll find they usually go on getting worse for some time; but when things once start going right they often go on getting better and better.”

“A man who first tried to guess 'what the public wants,' and then preached that as Christianity because the public wants it, would be a pretty mixture of fool and knave”

“If they are wrong they need your prayers all the more; and if they are your enemies, then you are under orders to pray for them. That is one of the rules common to the whole house.” 

“Indeed the safest road to Hell is the gradual one--the gentle slope, soft underfoot, without sudden turnings, without milestones, without signposts,...Your affectionate uncle, Screwtape.”

“if you do one good deed your reward usually is to be set to do another and harder and better one.”

“If we insist on keeping Hell (or even earth) we shall not see Heaven: if we accept Heaven we shall not be able to retain even the smallest and most intimate souvenirs of Hell.”

“The first demand any work of art makes upon us is surrender. Look. Listen. Receive. Get yourself out of the way. (There is no good asking first whether the work before you deserves such a surrender, for until you have surrendered you cannot possibly find out.)”