On the surface, books like this as well as ideas of "how to be a Christian" seem harmless enough. After all, what harm can come from a basic do this, don't do that, follow these 3 steps etc...formula (s)?
My first Pastor used to comment now and then on a popular preacher of the day who would often use step 1, 2, 3 and so on formulas in his teaching. My Pastor was concerned that you can't just lay out a plan and expect it to all come together. The gospel couldn't be learned like a text book formula, it had to be believed and only by the Spirit could that take place.
When we think if we do all the right things before God and our brethren that everything has to go right, we can often times set ourselves up for big disappointments. I've written a little about this before. Its actually a form of prosperity gospel. We just don't know it, until life smacks us in the face. People sin, some make false professions, others are raised in the Church and when they finally get freedom, they realize they really don't believe what mom and dad do. Regardless of the reason, even the most planned thought out "Christian" marriages can end in disaster.
I have an old friend and brother in the Lord who is a Pastor. He and his wife raised a son and a daughter to know the Lord, home-schooled, loved them in the Lord and tried hard to make sure they met and married other Christians. In spite of all that, his daughter (a professing Christian) only married for a short time, left her husband for another man. While she still may repent someday and we hope and pray she does, her husband has since re-married and so the devastation has already occurred.
In my own personal life, I've experienced pain and heartache from family and friends who are in the faith, but yet they fall into sin-sometimes even the most grievous of sins. Worst yet, I've done harm to myself (and others) by falling into sin that I never thought would happen after being saved. Do I give up because the formula and plan didn't work? It can be tempting (in the flesh), but in the end, I've leaned into the gospel even more. Not always easy, but these things have made it clear, that Christ is our all in all and no matter what, the gospel is our hope in everything.
Doing the right things, dotting our i's an crossing our t's are always good things. My friend who raised his kids in the Lord did the right thing, but when we think that means its always going to go well and work out as hoped, we may find ourselves sorely disappointed when sin and unbelief raise their ugly heads. I'm certain that many who read the book "I Kissed Dating Goodbye" and followed that advice are doing well in their marriages, but its not because they followed some formula. Its because their hope is in the Lord. The gospel keeps them, not the formula!