Exorcism 

Exorcism (from Greek εξορκισμός, exorkismós “binding by oath”) is the religious or spiritual practice of evicting demons or other spiritual entities from a person, or an area, they are believed to have possessed. Depending on the spiritual beliefs of the exorcist, this may be done by causing the entity to swear an oath, performing an elaborate ritual, or simply by commanding it to depart in the name of a higher power. The practice is ancient and part of the belief system of many cultures and religions. wikipedia