Based on a true story.
The central character is Michael Kovak, a seminarian student who questions his faith. But before he leaves the seminary, he agrees to attend an exorcism course in Rome. It is there that he meets Fr. Luca (Anthony Hopkins), an experienced exorcist. While working with Fr. Luca, Michael participates in several exorcisms and comes face to face with the devil. Michael is ultimately required to perform an exorcism on a most unexpected person and realizes that believing in God and His power over evil is necessary to overcome evil. Fr. Gary Thomas, upon whom Michael's character is based, is still an active exorcist in the Chicago area.
EWTN has been praising this film as being accurate about exorcisms. Indeed, it is a very good movie and there is no Catholic bashing. Anthony Hopkins is stellar as Fr. Luca.