Exorcism, practice of expelling demons or evil spirits from people or places that are possessed, or are in danger of possession, by them. Exorcism usually is performed by a person with special religious authority, such as a priest or shaman. The practice was common in ancient societies and was based on the practice of magic. Ancient Babylonian civilization, in what is now Iraq, had special priests who would destroy a clay or wax image of a demon in a ritual meant to destroy the actual demon. The ancient Egyptians and Greeks had similar rites. Many religions in various parts of the world continue the practice of exorcism. The Bible includes a number of references to demons and exorcism. The New Testament describes occasions when Jesus Christ expelled evil spirits by prayer and the power of his command. In the Roman Catholic church, exorcism is an order that priests may practice with special permission. It is mainly used as a preparation for the sacrament of baptism.