MEXICO CITY, MEXICO - MAY 31:  The priest Hugo Alvarez performs the exorcism ritual on a faithful at the Church of the Divine Saviour in Mexico City, Mexico, 31 May 2011. Exorcism is an ancient religious technique of evicting spirits, generally called demons or evil, from a person which is believed to be possessed. Although the formal catholic rite of exorcism is rarely seen and must be only conducted by a designated priest, there are many Christian pastors and preachers (known as ‘exorcistas’) performing exorcism and prayers of liberation. Using their strong charisma, special skills and religous formulas, they command the evil spirit to depart a victim's mind and body, usually invoking Jesus Christ or God to intervene in favour of a possessed person. (Photo by Jan Sochor/Latincontent/Getty Images)