"The Great Divorce" by C.S. Lewis is an exploration of the nature of the afterlife, as well as the conditions of a human life and how our lives turn us towards Heaven or Hell. In this fictionalized account of people living supposedly in purgatory, Lewis exaggerates some aspects of the afterlife and takes a few liberties with Christian theology to make his point very clear. Two major themes are human sin and the nature of Heaven and Hell.

Human Sin

The characters's own pettiness, anger, greed, loneliness, and lust drive them against and away from one another, making their eternities miserable. The idea that Lewis wants to show is that, if human sin is left uncorrected by the refining power of Christ, they will create Hell because their own nature and lives will become so twisted and corrupted that there is really no other option.

However, a counterpoint to their lives in Hell is the example of a man who has a beast on his shoulder, encouraging him to sin. When he finally chooses to eschew his sin and enter Heaven, the beast transforms, becoming a beautiful companion animal that aids him. It shows that the things in our nature that cause us to sin, when submitted to the right purpose, actually empower us and bring us closer to God. In this way, Lewis shows a method of being redeemed for one's sins.

The Nature of Heaven and Hell

The shocking and sudden twist in the novel is that there never was purgatory. As the humans leave their eternal destination to temporarily visit and be offered a final chance at attaining Heaven, they realize that the place they are living is Hell itself. Not only is it Hell, it is a Hell of their own creation. What is poignant (and has become a well-trod metaphor for the nature of sin) is that Lewis displays Hell as the result of an eternity of increasing sin and reckless unrighteousness in the characters's lives. There is no fiery torment, nor is there a company of demons to torture the members of Hell.

Upon reaching Heaven, however, the scene is reversed. First, the characters learn that Heaven is "more real" than anything they've ever seen. They pass through trees and rocks like ghosts because they, in their fickle nature, are fleeting and weak, whereas Heaven and the Heavenly things are much stronger and more permanent than their desires and sins.