Exorcism is the expulsion of demons and other unwanted spirits from a person or place. Rites of exorcism have been performed since ancient times as remedies against the negative or malevolent influences of spirits, such as the perceived cause of illnesses, bad luck, personal difficulties, obsession, and possession. The word exorcism is from the Greek exousia, meaning “oath,” and translates as adjuro, or “adjure,” in Latin and English. To exorcise does not really mean to “cast out” so much as it means to “put the Devil on oath,” or petition a higher authority to compel the Devil to act in a way contrary to his wishes.
In some cultures, demons are exorcised by loud noises, such as beating gongs and bells, and by beating the victim physically, in order to force the demons out of the body. In other methods, rituals for exorcism provide for less extreme measures through the use of holy objects, prayer, and commands.
Exorcism is considered dangerous for victim and exorcist, and even for onlookers, for expelled demons will immediately look for a new host, unless they are properly bound and dispatched.