Symbols are objects, characters, figures, and colors used to represent abstract ideas or concepts.
During the course of writing the twenty-second letter, Screwtape transforms into a giant centipede. . Screwtape explains becoming a centipede as an external sign of his inner “Life Force,” a positive sign. But, as usual, the reader should not take Screwtape’s message at face value. The centipede is a symbol of Screwtape’s contradictory nature. His transformation can be interpreted in a variety of ways. It can be seen as a curse, a punishment given him by God. This, says Screwtape, is how the poet John Milton described such occurrences in Hell. It can be seen as an irresistible change caused by his growing anger at Wormwood. Or, indeed, it can be seen according to Screwtape’s account, as a sign of his innate virility. This version of Screwtape may, in fact, be just as much his true self as his more humanoid, though never actually visually described, shape.
The noxious fog is only visible to spirits, not to humans, and it is only “noxious” (suffocating and very unpleasant) to devils. The noxious fog represents God’s divine grace. The Patient is protected by during his second conversion experience, which occurs while he is walking to an old mill. God’s healing gracea kind of spiritual energy that, according to Christian teaching, fills humans during moments of divine inspiration or during religious sacraments is a sign of God’s love, which devils are unable to tolerate. In addition to God’s grace, the noxious fog represents the limited influence devils have over human lives. They can guide humans into sin, they can encourage certain emotions, but God, because he is all-powerful, can stop them from influencing human lives at any time. The noxious fog also represents what might be called, within The Screwtape Letters, the inverse rule of Hell. Anything that is good or positive in human life, is noxious, disgusting, or insufferable for devils. For example, Godis “the Enemy,” and a “desirable marriage” between a man and a woman, for Screwtape, means one that will cause both people to sin and suffer.
The crucifix, in The Screwtape Letters, represents a distraction from prayer. Screwtape advises Wormwood that it is easy to trick humans into a kind of false, ritualized prayer, where they no longer pray to God, but to a representation of God that they hang on their wall. The crucifix is, therefore, also a symbol of idolatrthe worship of a false God. The Christian God is immaterial and the crucifix is meant to serve as a reminder of the suffering of his Son, Jesus Christ. Outside this reminder the crucifix offers of God’s love for human beings, it has no special power in itself. According to Christian teaching, it is a sin to imagine that it does. Within he Screwtape Letters, the crucifix is, furthermore, a symbol of Christian hypocrisy. People pray to the crucifix, but they spend no time whatsoever focusing on God’s love and the way God suffered for the redemption of their sins. This hypocrisy in prayer often carries on into other dimensions of Christian life.