Fireproof
(2008)

Fire Captain Caleb Holt (Kirk Cameron) and his wife Catherine (Erin Bethea), a hospital administrator, are on the brink of divorce when Caleb's parents suggest that he take "The Love Dare", a 40-day challenge that will save their marriage.

Caleb's parents took the dare a few years ago, and they say it saved their marriage and led them to become Christians.

Caleb reluctantly accepts the challenge, which calls for him to talk and act with care towards her, but Catherine is skeptical. She thinks he is just buttering her up to get more in the divorce settlement, so she ignores and fights everything Caleb does. She even becomes very friendly with one of the doctors at the hospital, which might lead to an affair. After 20 days, Caleb is ready to quit the challenge and get the divorce when his father comes to talk to him. Caleb asks how does someone continue to love you when they won't even give you a chance. His dad tells him that is exactly what God does to each one of us everyday. This eventually leads to Caleb accepting the Lord in his life.

The newly rejuvenated Caleb continues the challenge, this time with more effort than he was originally giving it. However, Catherine continues to resist, even going so far as to serve divorce papers to Caleb. Undaunted, Caleb continues the challenge, and Catherine slowly begins to come around to the fact that he is actually trying to save their marriage. At this time, Caleb finds out about the doctor, and threatens him to stay away from his wife, which he does. Catherine becomes more convinced about Caleb when she finds the book that his dad gave him which spells out the challenge. When she tells him that she found the book, Caleb tells her about his Christian transformation, and asks for her forgiveness in his actions. She is finally convinced when she discovers that Caleb paid for a new wheelchair and bedfor her bed-ridden mother using the money he was saving for a boat that he wantedbut she didn't. Catherine originally believed that the doctor had bought the items while they were together. Catherine goes to the
firehouse, where she asks Caleb to forgive her for her actions, and hopes it isn't
too late to save their marriage.

In the end, Catherine and Caleb reconcile, and she becomes a Christian herself. They later renew their vows in front of all of their friends and family.

Thanks Steve!