Based on the love story of two devout Christians, the movie version of "The Vow," starring Rachel McAdams and Channing Tatum, strips the tale of its overt religious themes, which has some Christian reviewers concerned.

The film is based on the true life story and book, “The Vow” by Kim and Krickitt Carpenter, which draws heavily on that couple’s Christian beliefs and the power of God to heal and shepherd a marriage through difficult times.

The book tells the story of Kim and Krickitt, who met and fell in love over a long distance phone call in 1992, bonded over their Christian faith, and were married a very short time later. Just 10 weeks into their marriage, the couple survived a terrible car wreck that left Krickitt in a coma with severe head trauma. Upon waking, Krickitt experienced amnesia and was essentially married to a stranger, forgetting the last 18 months of her life.

Throughout the book, it is the couple’s religious belief in the unbreakable vow of marriage that keeps them together.

“You make a promise before God with your wedding vows,” Krickitt Carpenter told Fox411.com. “You have to take that seriously.”

The studio version of the Carpenter’s marriage, however, strips the couple of their Christianity.

“The movie doesn’t talk about faith significantly. It would have been nice to see more of it,” Kim Carpenter told Fox411.com. “The first book we wrote was extremely embedded in our faith, but I think the movie does depict the inspiration of the battle to hang in there. I think the audience realizes we are a people of faith.”

Some movie critics would have liked to see more overt references to the couple’s faith as well.

“It was a sweet story but it didn’t have any power to it,” said Ted Baehr, the publisher of TheMovieGuide.org, a Christian family guide to movies. “Making it more secular diminished the power of the movie. It didn’t make sense that it was so sublimated to secular values. The real world consists of the 82 percent of Americans who believe in god who want faith and values in their films.”

The movie version of “The Vow,” rated PG-13, was a huge hit over the weekend, raking in over $40 million, and another $11 million on Valentine’s Day alone. But it is hardly family friendly fare. There are innuendos that the couple in the movie, named Paige and Leo, engages in premarital sex. One of the characters in the film has an extramarital affair. The couple’s wedding is non-denominational. They also get a divorce in the movie, something that the Carpenters vowed not to do in real life.

Sony Pictures did not respond to a request for comment.

Hollywood has not been a stranger to Christian themes in recent years. The movie “The Blind Side” was largely propelled to success because of, and not in spite of, the Christian values that it embraced.

So what made “The Vow” different?

“With a crowd pleaser like ‘The Vow,’ studios try to cast as a wide a net as possible with regard to possible audience. That often means sanitizing a movie as much possible,” explains Lilit Marcus, who writes the blog Faith Goes Pop on the Patheos network.

Some Christian audience members still found God in the flick, however.

“In my opinion, God is a huge part of 'The Vow,' albeit metaphorically,” said Shawn McEvoy, the managing editor of the Christian website Crosswalk.com. “The love with which Leo pursues Paige, even after she no longer really remembers or even wants him, is the tireless love with which God pursues His people.”

For their part, the Carpenters were just happy to see their inspirational story translated onto the big screen. They hope that the audience seeking the spiritual side of their story will turn to a re-released edition of their book.

"They took some artistic license that deviated from the real story, but that is all part of the process," Kim Carpenter said. "We are really excited about our book because that is the whole true story."