My husband and I grew up evangelical and this was the book we were advised to read during our premarital counseling! I hadn’t thought about it in years! It at least taught basic anatomy, emphasized women’s orgasms and that husbands needed to learn to please their wives sexually, and if they had trouble to seek out professional help.
Some of my friends went into their wedding nights thinking everything was going to magically be awesome, and wow were they disappointed. As messed up as a lot of this book was, it was actually pretty helpful for my husband and me. (We ignored a lot of it even then, though. We did not believe in the submissive wife thing.)
Still together, 25 years, we’re Episcopalian now.