Hysteria is a common cause of fears of demonic indwelling,night time cold sweats and nocturnal emissions are another.
Actual Demonic Possessions are extremely rare but they do happen. The Movie the exorcist was based on a true,well documented story,The writers 'jazzed' it up a bit but it's was true.The Catholic church has access to a few exorcists and the Vatican does not have a "school" for exorcists, despite occasional news stories that tout an annual course at Rome's Regina Apostolorum University in precisely that fashion.
Regina Apostolorum, which is sponsored by the Legionaries of Christ and their lay branch Regnum Christi, has hosted a brief course each year since 2005 on "Exorcism and Prayer of Liberation." The sixth installment is set to take place from March 28 to April 2, 2011, co-sponsored by a private Bologna-based foundation called the "Group of Socio-Religious
Research and Information" which tracks New Age religious movements and the occult.
Demonic evils in the world are real and to prove the point cast about for histories most evil and there is your proof......All of us can name those people in history who caused the greatest pain and injury to mankind and identify their great evil.
What motivated Hitler to attempt the extermination of The Worlds Jews,Gypsies and Slavics ?If the Jews are GODS chosen who then would destroy them other than GODS Demonic adversary .The Demon hates man because GOD Loves us and it is jealous of that love !