Themes are the fundamental and often universal ideas explored in a literary work.
The Screwtape Letters is predicated on an eternal struggle between the forces of good and evil. These forces are represented by the opposing camps of Heaven and Hell, God and Satan, angels and devils. These letters are presented with the expectation that readers have a basic understanding of Christian beliefs, such as the story of the Fall. The story does not occur in the Bible, but in it, Satan (then called Lucifer) and a group of angelic followers rises up against God. God, who is all-powerful, casts them out of Heaven and into eternal damnation. As a consequence of being banished from Heaven, Satan and his forces strive to “win” souls to their cause by tempting them away from God and virtue, and into vice and sin. The struggle between Heaven and Hell that began with Satan’s uprising plays out as a competition for human souls. Though God is all-powerful, he allows humans to make their own decisions. Devils like Wormwood and Screwtape try to trick humans into making the wrong ones.
Late in The Screwtape Letters, Screwtape complains that the Patient’s love interest, the Woman, and her family are merely Christian. They practice basic Christian principles without turning their belief in God and Christian teachings into a fashion statement. Screwtape advises Wormwood to use the Woman’s family’s political interests to corrupt the Patient. Instead of being merely Christian, the Patient might start to practice “Christianity and...” Wormwood should make the Patient interested in movements like, for example, Christianity and the War, Christianity and Vegetarianism, Christianity and Animal Abuse. This model of Christianity, in which Christian teachings become a sidecar for fashionable political agendas, is a way for Hell to corrupt the positive influence of Christian teachings on people’s lives, a way to make Christians less Christian. Lewis uses Screwtape’s position to criticize the political trends of his day. He argues that Christianity is about the simple practice of virtue, justice, and Jesus’s teachings in the gospels.
Mere Christianity is also the title of one of C.S. Lewis’s other books, a book based on the radio talks that Lewis gave from 1942-1944 during World War II. These talks were written and delivered just after The Screwtape Letters appeared in the Guardian newspaper, between May and November of 1941. Mere Christianity is, to a large extent, an expansion of themes Lewis began to explore in The Screwtape Letters. Practicing mere Christianity doesn’t just mean avoiding political specification and fashionable trends. It also means steering clear of divisions within Christianity, such as the split between Protestant groups and the Catholic Church. he small points of distinctions between Christian groups, whether, for example, the Communion bread and wine are actually the body and blood of Christ or simply a representation of it, re relatively points of faith. In The Screwtape Letters, Lewis implies that these small distinctions are only a distraction from the true call of Christianity—the call to live rightly.
The main literary device in The Screwtape Letters is satire. Satire is a literary mode in which an author makes light of commonly held beliefs or ideas by means of irony, humor, exaggeration, and ridicule. Irony occurs when an author suggests meanings or ideas that occur outside of the literal interpretation of his words. It is ironic, for example, that a devil, Screwtape, would accidentally give spiritual advice to the humans he means to tempt into Hell. Screwtape advises Wormwood to make sure the Patient does not think of his everyday obligations. Provided readers buy into the Christian pretext of The Screwtape Letters, they reinterpret Screwtape’s advice to mean something other than what Screwtape says. Instead of thinking how they can better tempt a soul into Hell, willing readers think of how they can better attend to their everyday obligations and, in so doing, thwart devilish temptation. For Wormwood, meanwhile, there is no irony in Screwtape’s suggestions. He is supposed to take Screwtape’s advice at face value. Interesting, then, that Screwtape fails to educate Wormwood about how to tempt the Patient’s soul into Hell. One of the implicit arguments of The Screwtape Letters is that satire adds entertainment to advice, education more effective.