This book was authored by John and Susan Townsend and has been used to teach seminars in several nations with excellent results. Since then it has been published and released to help whoever needs it. A more full but streamlined course is available "Marriage By God's Design Course" contained in the workbook with questions and answers. Both resources can be used with each other, but the book form here is more comprehensive and is best used by couples or singles contemplating marriage to read together.
The book is also useful to meditate on issues that arise when God's principles have already be violated, to help work out how best to live under His graces.