C.S. Lewis on Heaven and Triumph Over EvilThe Great Divorce (Simon & Schuster: 1946), 116.
“No, Frank, not here”, said the Lady. “Listen to reason. Did you think joy was created to live always under that threat? Always defenseless against those who would rather be miserable than have their self-will crossed? For it was real misery. I know that now. You made yourself really wretched. That you can still do. But you can no longer communicate your wretchedness. Everything becomes more and more itself. Here is joy that cannot be shaken. Our light can swallow up your darkness: but your darkness cannot now infect our light. No, no, no.
Come to us. We will not go to you. Can you really have thought that love and joy would always be at the mercy of frowns and sighs? Did you not know they were stronger than their opposites?