Gerard Butler had to prove he was up to playing his character in new film Machine Gun Preacher.
The Hollywood heartthrob portrays Sam Childers, a renegade biker-turned-preacher who founded an orphanage in Sudan in the film, which is based on a true story, and went to meet Sam at his home in Pennsylvania to discuss the role.
Gerard said: "I know he had his doubts, because he has doubts about all of Hollywood, to be honest. I think anybody like that will think, 'He's an actor, how can he be a bad***?' But I am."
The 41-year-old actor - whose parents divorced when he was a toddler, and who didn't see his father again until he was 16 years old - revealed he found an affinity with Sam.
Gerard said: "I connect with people who have a lot of pain.
"Much as I could have fun with Sam, I really connected with him when he talked about his life or the guilt that he felt. It made me want to hug him and do justice to the story.
"When I first read the script, I thought, 'Are you kidding me?' This couldn't all have happened, but it did - and much more.
"Sam has experienced more than most people would in 10 lifetimes.
"I've never met anybody who I'd heard so many things about. Everybody said they knew him, that he was crazy, cunning, or hilarious."
:: Machine Gun Preacher is in cinemas now.