Exorcism (from Greek εξορκισμός, exorkismós "binding by oath") is the religious or spiritual practice of purportedly evicting demons or other spiritual entities from a person or an area they are believed to have possessed. Depending on the spiritual beliefs of the exorcist, this may be done by causing the entity to swear an oath, performing an elaborate ritual, or simply by commanding it to depart in the name of a higher power. The practice is ancient and part of the belief system of many cultures and religions.
Requested and performed exorcisms had begun to decline in the United States by the 18th century and occurred rarely until the latter half of the 20th century when the public saw a sharp rise due to the media attention exorcisms were getting. There was “a 50% increase in the number of exorcisms performed between the early 1960s and the mid-1970s”.
In Christianity, exorcism is the practice of casting out demons. In Christian practice 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.