In the course of the 20th century, Pentecostalism expanded from a small revival movement to a global presence comparable in its extent and variety to Roman Catholicism or Anglicanism. Yet few people in mainstream U.S. churches know much about it, and what little they do know relates more to Pentecostal practice than to Pentecostal thought.
Richard Gallagher, a board-certified psychiatrist and professor of clinical psychiatry at New York Medical College, was skeptical when a priest/exorcist asked his opinion of a woman diagnosed with demonic possession. In time Gallagher’s scientific habits of observation led him to believe that in rare cases, the only explanation for bizarre behavior is that it’s the work of evil spirits. Over the past 25 years he has consulted with hundreds of ministers, helping them to distinguish between mental illness and demonic possession. Gallagher, a practicing Catholic, is working on a book about demonic possession in the United States (Washington Post, July 1).