Exorcism in Christianity
Exorcism in Christianity is the practice of casting out demons from a person they are believed to have possessed. The person performing the exorcism, known as an exorcist, is often a member of the Christian Church, or an individual thought to be graced with special powers or skills. The exorcist may use prayers and religious material, such as set formulas, gestures, symbols, icons, amulets, etc. The exorcist often invokes God, Jesus and/or several different angels and archangels to intervene with the exorcism. A survey of Christian exorcists found that most exorcists believe that any mature Christian can perform an exorcism, not just members of clergy. Christian exorcists most commonly believe the authority given to them by the Father, Son, and Holy Spirit (the Trinity) is the source of their ability to cast out demons.
The Exorcist (film)
Both priests witness Regan perform a series of bizarre, vulgar acts. They attempt to exorcise the demon, but the stubborn entity toys with them, especially Karras. Karras shows weakness and is dismissed by Merrin, who attempts the exorcism alone. Karras enters the room later and discovers Merrin has died of a heart attack. After failing to revive Merrin, the enraged Karras confronts the mocking, laughing spirit, and wrestles Regan's body to the ground. At Karras's invitation, it leaves Regan's body and possesses Karras. In a moment of self-sacrifice, the priest throws himself out of the window before being compelled to harm Regan. He is mortally injured. Father Dyer, an old friend of Karras, happens upon the scene and administers the last rites to his friend.