‘Miracles’ mom ‘humbled’ to be played by Jennifer Garner

It wasn’t Christy Beam’s idea to have Jennifer Garner, or any other movie star, portray her.

When approached about a film adaptation of her memoir, “Miracles From Heaven” — an account of how Beam’s daughter Annabel survived a harrowing accident and surmounted an unrelated, life-threatening medical crisis — Beam, 43, politely refused to offer advice on casting. “I said, ‘I don’t do that for a living,’ ” she says. “But when I found out it was Jennifer, I was so honored and humbled.”

For Garner, also 43, the decision to play Beam in the film (in theaters Wednesday) was a no-brainer. “I stayed up all night reading the script with a knot in my stomach,” the actress says.

At that point, Beam’s book, published last April, wasn’t even out yet. But author and preacher DeVon Franklin had a tip from a friend who knew Beam had a book deal. Franklin loved the concept, as did his fellow producers T.D. Jakes (also a pastor, who shares Beam’s literary agent) and Joe Roth (Jakes’ partner in producing the inspirational 2014 film “Heaven Is for Real”).

“Everyone felt this would be a fantastic follow-up,” says Franklin, and screenwriter Randy Brown was enlisted to adapt Beam’s book.

In the movie, 12-year-old Kylie Rogers plays Annabel (often called Anna) who suffers from a rare disorder that leaves her unable to digest food. Following a long ordeal that upends the lives of Christy’s husband and their two other daughters, Anna suffers a potentially fatal accident, but emerges relatively unscathed, and seemingly cured.

Faith has long played a role in Garner’s life: She and estranged husband Ben Affleck had their three children baptized at the same United Methodist church she attended while growing up in West Virginia. “My parents and little sister and her family still go there,” Garner says.But “I think I had become complacent in raising my children, almost as though (I thought) they were going to receive the ground beneath their feet that heaven had given me through osmosis,” she says. Returning home after filming, Garner raised the subject with her kids, “and they said, ‘Well, we want to go to church.’ ”

Garner “was floored, and I immediately looked up the local United Methodist church. We went there next Sunday, and it turned out to be the perfect environment. We’ve gotten so much from it; it’s like a gift Christy gave me.”

She and Beam “talked about everything” during filming, Garner says. “No stone was left unturned, from how she kept her nails while she was in the hospital to what her favorite hymns are from church, so I could make a playlist.”