Belief in the devil and other evil spirits of the Christian tradition is a topic that has been widely discussed in recent years. Since the release of movies such as 'Rosemary's Baby' and 'The Exorcist', more people are wondering, Is Satan really dead? Is there such a phenomenon as obsession or possession? In 'The Devil, Demonology, and Witchcraft', Henry Ansgar Kelly postulates his belief that the existence of evil spirits is not probable and suggests that Christians would be better off acting on the assumption that they do not exist. To prove his claim, the author sets forth a history and analysis of the impact of demonological traditions developed within Judaism and Christianity over the centuries. He then considers the incorporation of these notions into early Christian teaching with the resulting demonological dotrines of witchcraft, possession, and temptation. Kelly's conclusion is that Satan is dead, and demonology should be eliminated from Christian dogma since, according to his thesis, these manifestations in the Bible reflect the beliefs of local cultures and not divine revelation. The present edition has been substantially revised and updated by the author to include an evaluation and critique of 'The Exorcist', wherein Kelly challenges William Peter Blatty's facts of the alleged possession in 1949 on which 'The Exorcist' is based.