Fireproof by Alex and Stephen Kendrick

I read,in one sitting,the novelization of the screenplay Fireproof. It was a very good book and I would definitely recommend it to anyone over the age of 15.
It starts out with a married couple--Caleb and Catherine Holt. Caleb is a Captain of a battalion of firefighters and spends most of his time at the station. Catherine is a public relations manager of a local hospital and the couple have been married seven years. However, the spark has died and they are constantly fighting. Caleb is putting away a third of his salary for a boat he wants, and Catherine is accepting the attention of a male doctor at work.
After a particularity nasty fight, Catherine asks for a divorce, and Caleb readily agrees. Caleb tells his father John about the impending divorce and John challenges Caleb. John asks Caleb to wait 40 days before getting a divorce and go through a "love dare". He sends Caleb a book and Caleb starts doing the love dare.
The first day is to refrain from saying anything negative to your spouse. Caleb does it, but notes that this isn't going to be easy. Then next day the challenge id to say something positive to your spouse. Again Caleb does it but this time he is rebuffed. The dare continues and Catherine rejects Caleb again and again. Caleb vents his frustration to his father and John asks him if he is reading the Scriptures at the bottom. Caleb says he isn't and John remarks that that is the problem.
Caleb doesn't want to get into "all that Jesus stuff" but after his father explains what it is all about, Caleb accepts the Lord as his Savior. With his heart now in this dare, Caleb tries harder. Caleb find a note that is to Catherine from another man telling Catherine how much he enjoys her company. Finding out that it is a doctor at the hospital he goes and makes it very clear to the doctor that Catherine is his wife.
I'm not gonna spoil the ending, but I will tell you that Caleb and Catherine do work things out.
A books that sometime in your life you need to read is definitely Fireproof