Deadline is reporting that Gerard Butler is teaming with director Marc Forster for Machine Gun Preacher, which tells the story of Sam Childers, a former drug-dealing biker tough guy who found God and became a crusader for hundreds of Sudanese children who've been kidnapped and pressed into duty as soldiers.

Co-written by Forster and screenwriter Jason Keller, the film is based on Childers' book "Another Man's War: The True Story of One Man's Battle to Save Children in the Sudan."

Production could start as early as later this year.