A former ESPN camera operator, Andy Erwin remembers shooting Super Bowl XXXVI when the St. Louis Rams took on the New England Patriots at the Louisiana Superdome in New Orleans in 2002.

On one end was Kurt Warner — who became part of “Super Bowl lore,” going from grocery store stockboy to two-time NFL MVP in the space of a few years — and on the other was Tom Brady, who at the age of 24 helped lead the Patriots to a 20-17 win in a game that heralded the Patriots’ dynasty.

But to Erwin, one moment that really stood out was when he caught a glimpse of the bond between Warner and his wife Brenda.

“I just watched how he interacted on the sidelines with this spiky haired, tattooed Marine, beautiful lady in the stands, and that was his wife Brenda. The partnership between those two, I was like, ‘I want to know the story behind that,’” Erwin said in an interview.

Twenty years later, Erwin is telling that story.

“American Underdog,” a biopic of Warner’s life directed by Erwin and his brother Jon, opens in theaters on Christmas Day. The film had its red carpet premiere in Los Angeles on Wednesday.

Starring Zachary Levi, Anna Paquin and Dennis Quaid, the movie is one of other faith-based releases from the Kingdom Story Company, which includes “I Still Believe,” based on the real-life story of chart-topping singer Jeremy Camp, and “The Jesus Revolution,” inspired by the true story of a national spiritual awakening in the early 1970s.

“American Underdog” focuses on Warner and Brenda’s relationship — beginning with their first encounter at a country bar. The two fall in love, but life together is not a quick and easy happy ending. An undrafted Warner works at a Hy-Vee grocery store in Iowa, as the couple navigate financial struggles, uncertainty around Warner’s football career and raise her two children, one with disabilities. Warner finally finds some success as an arena football star before he’s given a shot with the NFL when he gets called up by the St. Louis Rams.

One scene shows the couple struggling so much they run out of gas in the middle of a snowstorm as they drive to Warner’s mother’s house to find a warm place to stay. Warner, with a few dollars, runs a few miles to the gas station and back. He returns to find their truck covered in snow, with the family safe inside, but recognizing the danger his family was in.

Throughout the film, you see glimpses of the role their Christian faith plays in the choices they each make.

Early in the movie, Brenda, who was divorced with two children, tells Warner of her early aspirations to join the Marines and start a life in “God country” after a woman at church told her, “God is going to do something great with you.”

The movie details how her ex-husband was unfaithful while she was pregnant with their second child and how her son went blind after her ex-husband accidentally dropped him when he was just four months old. She calls her son a miracle.

As they begin a relationship, Warner asks Brenda if religion is important to her, and she responds by telling him her relationship with God defines her.

As his efforts to play pro football seem bleak, a frustrated Warner, who at one point is on food stamps, vents to Brenda about whether he should give up. “I’m just wondering why God would give me a dream that’s probably never going to come true because I just feel like that’s cruel,” Warner says.

Brenda stands by his side and tells him “to go fight for it.” Just as Brenda encourages him to pursue his football dreams, Warner motivates her to continue school even amid their financial struggles.

Throughout his NFL career, Warner didn’t shy away from publicly expressing his Christian faith.

After winning his first Super Bowl with the Rams in 2000, Warner famously declared: “Well, first things first, I’ve got to thank my Lord and Savior up above … thank you, Jesus!”

When Warner advanced to Super Bowl XLIII with the Arizona Cardinals, he said: “There’s one reason I’m standing up on this stage today, that’s because of my Lord up above. I got to say thanks to Jesus.”

And, during his Hall of Fame speech, he said it was “the only place this extraordinary journey can end. His final moment was for me. Mine is for him. Thank you Jesus.”

To Erwin, faith is very much a part of the tapestry of sports culture.

“For Kurt, he was one of the first in my young adult life that I remember being as bold as he was with it. He was one of those first to step out and say, ‘This is who I am,’” Erwin said.

“We felt it was a unique opportunity to tell a story that was mainstream and broadly relatable without having to apologize for who they are and what they believe,” Erwin added. “We worked really hard to blend that world in a way that feels as authentic as the world it comes from.”

In making this movie, Erwin said he learned “what produces the heart of a champion.”

While Warner had the drive, it was through life’s circumstances, the love of his family, Brenda and “through her faith … that’s what really gave him the ability to fight through what he did.”

Alejandra Molina is a national reporter for Religion News Service.