Some writers have said that the flames of hell are not real flames but mere metaphors for the agony of being left to ourselves. I think this is probably true, but remember that a metaphor is just a shadow of the real thing; if flames are a mere metaphor for that agony, the agony must be worse than flames. Other writers have said that no one ends up in hell unless he wants to be left to himself. Again I think this is probably true, but isn’t being left alone what we all want when we sin? In hell, God merely gives us what we’ve wanted all along, and He lets the horrible natural results of our choices take full effect! We hate it, but there’s no place else we’d like better. Suppose He puts us in heaven instead. (He wouldn’t, because He won’t have sin near Him, but let’s pretend.) In our sinful condition, heaven itself, would be hell to us. The very radiance of His love would make our skin peel.
— J. Budziszewski, from How to Stay Christian in College, p. 42