Captain Caleb Holt (Kirk Cameron) is a firefighter in Albany, Georgia and firmly keeps the cardinal rule of all firemen, "Never leave your partner behind". But Caleb's home life is an altogether different story; his seven-year marriage to his wife Catherine (Erin Bethea) is on the verge of implosion. Neither one understands the pressures the other faces, and after a heated argument in which Caleb screams in Catherine's face, she declares she wants out of the marriage, and takes off her wedding ring.While Caleb claims to his friends and co-workers that Catherine is over-sensitive and disrespectful, Catherine simultaneously claims to her peers that Caleb is insensitive to her needs and doesn't listen to her. Further catalyzing Catherine's motivation for divorce is Caleb's addiction to Internet pornography and a large sum of money ($24,000, to be exact) he has saved up for a fishing boat he intends to buy, ignoring the fact that Catherine's disabled mother is in need of hospital equipment that she cannot afford, and which insurance refuses to cover. Caleb tells his father John about the impending divorce, and John challenges Caleb to commit to a 40-day test called, "The Love Dare." Caleb reluctantly agrees to do the test, but more for the sake of his father than his marriage. Catherine initially sees through Caleb's half-hearted attempts to win back her heart, which deepens Caleb's frustration. But with his father's encouragement, Caleb continues with The Love Dare, and eventually makes a life-changing commitment to God, unbeknownst to Catherine.Meanwhile, Catherine begins flirting with Dr. Gavin Keller (Perry Revell) at the hospital where she works. She begins to open up to him about some of her problems, chiefly her mother's need for the hospital equipment which she can't afford, but as she's no longer wearing her wedding ring, Keller doesn't know Catherine is married, at least not until Caleb is brought to the hospital later. Catherine comes up to Caleb in the emergency room as Keller is treating him, and a nurse says that Caleb is Catherine's husband. Caleb learns from Michael that he is divorced from a previous marriage that ended badly and has left him deeply ashamed and heartbroken since he committed to God while she had already remarried. Michael urges Caleb to keep himself committed to Catherine.Through the guidance of The Love Dare, and as a result of his commitment to Christ, Caleb begins to understand what it means to truly love his wife. He begins pulling more of his own weight at home, doing household chores and running errands, and even leaving real roses for Catherine. Soon Caleb even finds the motivation to destroy his computer and everything on it, smashing it to pieces with a baseball bat. However, Catherine is still intent on filing for divorce, much to Caleb's anguish.When Catherine goes to the home care store to talk with a clerk about the unpaid equipment her mother needs, the clerk tells her that all the equipment has been paid for in full and is being installed at her mother's house. Convinced it was Dr. Keller that paid the $24,300 price, Catherine goes to Keller at the hospital to thank him and sets up a lunch date with him. Meanwhile, Caleb finds out about Dr. Keller through a card for Catherine that she left at home, so he goes to the hospital and warns Dr. Keller that, even with his mistakes, he will not step aside and let Keller have Catherine without a fight. The doctor gets the message and quickly cools the relationship with Catherine, and the viewer learns that Dr. Keller is married and hides his ring in a desk drawer.When Caleb finds Catherine at home sick in bed, he decides to take care of her, with food and medicine. Bewildered at his new bedside manner, Catherine asks Caleb what's happening to him. Caleb starts to tell Catherine about The Love Dare, and she pulls Caleb's book out from underneath the blanket next to her. Caleb tearfully apologizes for his selfish behavior and asks her forgiveness. While Catherine admits she sees some change in Caleb, she still cannot bring herself to trust him and believe he has changed. Caleb understands and gives her as much time as she needs to think things over.Days later, Catherine returns to the home care store to purchase linens for her mother's new hospital bed, mentioning to the clerk that linens were the only thing Dr. Keller didn't pay for. But when the clerk reveals to Catherine that it was Caleb two weeks prior who paid $24,000 (Keller contributed only $300), Catherine bursts into tears and leaves the store. Now fully convinced of Caleb's genuine change of heart, Catherine runs home crying to put her wedding ring back on her finger. After freshening up, she goes straight to the fire house to tell Caleb that she now forgives him, and the two lovingly embrace. (Also, in a deleted scene, Catherine discovers Gavin flirting with a nurse shortly after learning of Caleb's payment for the hospital bed.)Caleb's parents come to visit. While talking to his son, Caleb's father reveals that, contrary to what Caleb had believed, he did not do The Love Dare on his wife, she did it on him. This causes Caleb to recognize the impact his mother has had in his life, and rushes home to reconcile with her. Caleb and Catherine renew their vows in an outdoor ceremony, this time as a covenant with God.