This is a rush transcript from "Hannity," May 1, 2009. This copy may not be in its final form and may be updated.

SEAN HANNITY, HOST: Our continuing "Beyond Belief" series takes a look at mysterious religious practices around the world. Tonight, we take a look at exorcism.

(BEGIN VIDEO CLIP)

FATHER MERRIN AND FATHER KARRASS, "THE EXOCIST": The power of Christ compels you.

HANNITY (voice-over): Exorcist, one to expel evil spirits by conjuration or exorcisms.

MERRIN: By the judgment of the living and the dead to depart from this servant of God.

HANNITY: Horrific images of girls screaming in agony, their bodies twisting and contorting in unhuman ways. In truth, such theatrics are quite rare. But the actual rituals are not.

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Father Gary Thomas is a Catholic priest in a California. He is one of the few priests trained to be an exorcist. In 2005, he was selected by his bishop to attend a Vatican-sponsored course on exorcisms.

GARY THOMAS, CATHOLIC PRIEST: When I went off to Rome on my sabbatical, there was a course being taught at the Regina Apostolorum Seminary at the time on exorcism and deliverance. And then, I took the initiative and found an exorcist in Rome, from whom I could receive from him some hands on training and mentoring. That is how I became a mandated exorcist of the dioceses.

HANNITY: In this class, Father Gary befriended Matt Baglio, a freelance journalist who was taking the class for research purposes.

MATT BAGLIO, JOURNALIST: When I met Father Gary, I was very surprised by his openness, his humility. He was very honest to me that he didn't anything about exorcisms and I found that to be fascinating. Why don't priests know this stuff? Why aren't they taught things about the devil and exorcism?

HANNITY: Baglio combines his research and Father Gary's training in his new book, "The Rite: The Making of a Modern Exorcist."

BAGLIO: I was able to follow him through his training and we were just able to share our experiences and really go on this journey together.

HANNITY: A journey that dates back to the days of Jesus.

THOMAS: There is also plenty of places found in the gospels where Jesus clearly performed exorcisms and didn't simply give people up.

HANNITY: Father Gary has performed over 40 exorcisms and he knows first hand what an encounter with a demon is like.

THOMAS: Most people have to invite a demon in to themselves. I use the word metaphorically, a doorway. You have to open a door to allowing demon the possibility to enter. When you pray deliverance prayers or you pray the right of exorcism, they can agitate the demon. And demons don't want to be agitated. They want to be secretive. They want to be silent. They don't want to give up their name. They don't want to have anything to do with the sacred and the holy.

BAGLIO: One of the things that surprised me the most when I started to see exorcisms was the relative normalcy of the people involved. I think most people assume the reactions are always going to be violent and that is just not the case. The majority of cases that these exorcists see are very mild. Now in a very few instances, there are said to be very strong reactions. I saw a few where the person's personality changed and their voice became very guttural and rough.

HANNITY: The reality is, few people realize what actually takes place during the rarely spoken about Catholic ritual, until now. What you are about to hear is audio from an actual exorcism that Baglio recorded in Rome.

UNIDENTIFIED FEMALE: I am going to let this b**** die.

(CACKLING)

What did the Nazarene say?

(CACKLING)

BAGLIO: During the ritual in the exorcism prays over the person and the person loses consciousness. And that is when you see these dramatic reactions, the eyes rolling up or rolling down with lights showing and the rough, guttural voice.

UNIDENTIFIED FEMALE: This woman is in my hands. In my hands.

(CACKLING)

THOMAS: Those prayers have power. And people aren't acting these things out because in a sense, they lose control when the demon begins to be agitated. They have no control over that. Sometimes they are not even aware it is happening.

UNIDENTIFIED FEMALE: Take your hands off my head. And do it now.

Upon yours.

(SCREAMING)

THOMAS: They will do all that they can to hide from anybody who invokes them to come out, to free the party from the state of obsession.

UNIDENTIFIED FEMALE: It's all a waste of time.

HANNITY: But convincing people that exorcisms are real is still a tough task.

BAGLIO: Once I started reading up on the theology and then later once I participated in exorcisms, I really got to see it in a new light. Exorcists don' have magical powers. They aren't charismatic individuals who have this ability to cast out demons at the snap of a finger. Really, the power comes through the prayer.

THOMAS: Just because we cannot see something or feel something or measure something does not mean that it does not exist. And Satan's great deception is convincing people that Satan does not exist.

HANNITY: So are demonic possession and exorcism rituals the products of an overactive imagination? Exaggerated plots of Hollywood movies? Or are they simply beyond belief?

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