The true story behind The Rite is based on the career of Father Gary Thomas, a priest who's been an exorcist for decades. Like The Exorcist, The Rite was based on a true story. The film drew much of its narrative from the book The Rite: The Making of a Modern Day Exorcist by Matt Baglio, which outlines the true story of Father Gary Thomas and his exorcisms.
Nowadays, Father Gary Thomas splits his time between giving interviews, running his rather large ministry, and performing exorcisms. It's important to him that the truth about exorcism as a practice reach a wider audience, so those in danger can find the help they need.
Father Gary Thomas had an integral role in the development of The Rite. At a time he spent over a week in Budapest, where most of the film was shot, offering criticism and insight to the creators. Anthony Hopkins reportedly received coaching on how to properly portray an exorcism from Father Thomas, which included everything from how to wear a stole to how to punctuate the prayers. The creative staff of The Rite was deeply interested in accuracy, according to Father Thomas.
Since the appointment of Pope Francis in 2013, there's been a resurgence in demands for exorcisms. In fact, it's been reported that Pope Jean Paul II issued a mandate requesting every bishop appoint and train an exorcist for their diocese. Part of this training may include a week-long training course in the Vatican, designed to prepare priests for duties as an exorcist.
In Father Gary Thomas's case, this training ended with him tutoring under Father Carmine, a Roman exorcist, for three-and-a-half months. He observed exorcisms, helped the discernment team, and participated in the rite to gain the hands-on experience he needed to expel evil.
Demons can be surprisingly legalistic, according to Father Gary Thomas. He says the power of an exorcism comes from the faith of those involved but also from the approval of the Catholic church.
Part of this approval means using the correct language to perform the rite. Latin is the traditional language of exorcisms, and the most hated language to demons, according to Father Thomas. However, in a pinch, approved translations of Italian, Spanish, and Portuguese are available for use. Demons have apparently even been known to tease exorcists who do not use an approved translation. This means parishioners who speak other languages, like Father Thomas's native English, are out of luck when it comes to understanding the rite being administered to them.
Communicating with demons is definitely on the Catholic Church's list of things not to do, but for an exorcist it can be unavoidable. As pointed out in The Rite, ascertaining a demon's name and purpose is the first step in asserting control.
For Father Thomas, this means praying for the safety of his team and then beginning a grueling interrogation into the nature of the demon involved. This interrogation always contains only three questions: "What is your name?", "How did you get in?", and "When are you leaving?" He says that obtaining answers to these questions is a sign the demon is losing strength. Once the demon's strength is depleted, he can begin casting it out with prayer.