Hell

All I have ever said is that the N.T. plainly implies the possibility of some being finally left in “the outer darkness.” Whether this means (horror of horror) being left to a purely mental existence, left with nothing at all but one’s own envy, prurience, resentment, loneliness & self conceit, or whether there is still some sort of environment, something you cd. call a world or a reality, I wd. never pretend to know. But I wouldn’t put the question in the form “do I believe in an actual Hell.” One’s own mind is actual enough. If it doesn’t seem fully actual now that is because you can always escape from it a bit into the physical world—look out of the window, smoke a cigarette, go to sleep. But when there is nothing for you but your own mind (no body to go to sleep, no books or landscape, nor sounds, no drugs) it will be as actual as—as—well, as a coffin is actual to a man buried alive.

- The Letters of C. S. Lewis to Arthur Greeves
Though Our Lord often speaks of Hell as a sentence inflicted by a tribunal, He also says elsewhere that the judgement consists in the very fact that men prefer darkness to light, and that not He, but His “word,” judges men. We are therefore at liberty—since the two conceptions, in the long run, mean the same thing—to think of this bad man’s perdition not as a sentence imposed on him but as the mere fact of being what he is. The characteristic of lost souls is “their rejection of everything that is not simply themselves.”

- The Problem of Pain