After my husband and I both read this book, we required our four older teenage/young adult children to read it so that they would have the insight for their future relationships. We also give this book to our friends and family as they get engaged to be married. I would highly recommend this book!
The Keller's brought together an excellent and forthright book about Christian marriage. And, unlike most books of this kind, it is actually very biblical. Finally, authors who took the famous wife/husband passage (Eph 5:22:33) and treated it as fruit of Eph 5:19 "...be filled with the Spirit". I have a minor quibble about being "blessed" in the O.T. as equivalent with being Spirit filled in the N. T., but that is certainly of no concern. I gave this book to my unmarried children and other married couples I know.
Time Keller's book is a very thorough look at marriage. It's not just a "this is what you do to have a better marriage" book, although if you apply what you learn your marriage will certainly improve. It looks at marriage from a biblical perspective - highly recommended!