In the Holy Bible, Jesus is described as casting out a demon on a number of occasions, and he instructs his disciples to do the same after he has gone. This practice has grown within the Christian tradition to be known as exorcism, a ritual practice which claims to be expel evil spirits or supernatural beings from the bodies or locations of those deemed to be possessed. Exorcism, however, is not merely a Christian practice, but has a history in most major world religions. All cultures, it appears, are concerned with the presence and hauntings of spirits, ghosts, demons, and evils, and have designed practices to help counteract these hauntings and provide comfort and safety to the possessed.

Perhaps one of the most famous exorcisms was that performed on Robbie Mannheim in 1949, which later inspired a number of books and movies like The Exorcist. Mannheim's tale is a particularly "exotic" exorcism, as it involved multiple priests and was recorded in detail through a diary. The story of Mannheim's exorcism exemplifies a few key characteristics of an exorcism.

For instance, it is generally not proper in the Catholic church, and in most religions, for just anyone or even for just a regular religious caretaker to perform an exorcism. Usually, permission from a higher religious figure is required (like an archbishop, in this case), and Catholic exorcisms is usually performed by a bishop. Also, those possessed by evil spirits are generally regard as innocent of acts they perform while under the supposed control of the evil spirits.

One might think that exorcisms have waned over the years with the advent of modernity, but there is strong evidence that exorcisms have actually increased over the last century, in large part because of their portrayal in more vivid media (like movies, television shows, etc.). This suggests that part of the draw of exorcisms is the spectacle of the possession and the ritual--people are intrigued by what startling things someone might do while under the "control" over an unknown being.

Today, professional exorcists--some connected to a particular religious tradition and others who are not--make themselves available to perform not only bodily exorcisms but the "purification" of houses and other locations from the influence of supposed evil spirits and demons. It would appear that exorcism and other forms of casting out a demon will most likely remain a part of contemporary culture for years to come.