'War Room' Star Priscilla Shirer Says She 'Sobbed' on Her First Day of Filming

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The low-budget faith-based film War Room has climbed the charts to become the No. 1 movie at the box office, making star Priscilla Shirer a Hollywood celebrity overnight.

"I'm grateful that God let me be a part of this project that is obviously blessing and touching so many people," Shirer told ET of the movie's success. "It's less about the hoorah of being in a movie and more about the opportunity that it is to be a part of a movie that's drawing people towards spiritual things and towards the importance of prayer."

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With War Room being her first movie ever, Shirer said she "broke down and cried" on her first day filming.

"I sobbed because I realized how nervous I was," Shirer said. "I think it was occurring to me, 'I'm going to be in a movie.'"

In the film, a couple struggling to stay together is encouraged to establish a war room, where they can battle their issues through prayer. Shirer was able to deliver a powerful performance by drawing on her real life as a wife and mother to three boys.

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Big-name actresses reportedly wanted Shirer's role, but she was cast because, she's also an inspirational speaker and Bible teacher.

"Acting on film is the exact opposite of being in front of a large crowd," Shirer said. "I had to rein in my impulse to project and do all the things I normally have to do when I'm standing in a stadium or a large church."

Her church home, Oak Cliff Bible Fellowship, was founded by her father Dr. Tony Evans and draws a crowd of 7,000 to 10,000 people every Sunday.

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The big question following War Room's success is whether Shirer will do another movie. While she seemed unsure, the door of opportunity is still open.

"If there was a project that came along that gave me an opportunity to still ride in line with the purpose that I know has been set before me for my life, and it involved acting, I would be open to it," Shirer said.

Shirer's latest book, Fervent, inspired by War Room, is on sale now.