Exorcism
In Catholic Christianity, exorcisms are performed in the name of Jesus Christ. A distinction is made between a formal exorcism, which can only be conducted by a priest during a baptism or with the permission of a bishop, and "prayers of deliverance" which can be said by anyone.
The Catholic rite for a formal exorcism, called a "Major Exorcism", is given in Section 11 of the Rituale Romanum. The Ritual lists guidelines for conducting an exorcism, and for determining when a formal exorcism is required. Priests are instructed to carefully determine that the nature of the affliction is not actually a psychological or physical illness before proceeding.
Exorcism in Christianity
The Lutheran Church traces the practice of exorcism to the Scriptural claim that Jesus Christ expelled demons with a simple command (Mark 1:23–26; 9:14–29; Luke 11:14–26). The apostles continued the practice with the power and in the name of Jesus (Matthew 10:1; Acts 19:11–16). Contrary to some denominations of Christianity, Lutheranism affirms that the individual, both the believer and the non-believer, can be plagued by demons, based on several arguments, including the one that "just as a believer, whom Jesus Christ has delivered from sin (Romans 6:18), can still be bound by sin in his life, so he can still be bound by a demon in his life."