Exorcism
In Catholic practice the person performing the exorcism, known as an exorcist, is an ordained priest. The exorcist recites prayers according to the rubrics of the rite, and may make use of religious materials such as icons and sacramentals. The exorcist invokes God—specifically the Name of Jesus—as well as members of the Church Triumphant and the Archangel Michael to intervene with the exorcism. According to Catholic understanding, several weekly exorcisms over many years are sometimes required to expel a deeply entrenched demon.
The Exorcist
The Exorcist is a 1971 novel by American writer William Peter Blatty. The book details the demonic possession of twelve-year-old Regan MacNeil, the daughter of a famous actress, and the two priests who attempt to exorcise the demon. It was published by Harper & Row.