There are some real problems with this book. I finished it, because there were a few helpful nuggets I could take away, but in general, I have some serious objections.
First, maybe I live under a rock, but it's not immediately apparent from the front cover, back blurb, or early chapters that this book has religious undertones. Religious nonfiction is great for some people and has an important place, but, as I've said with novels that try to sneak a message in in the last quarter, be upfront about it. No mention of religion in the first four chapters, then one mention in chapter five, and three in chapter seven strikes me as dishonest.
Second, like many self-help books, this presents a one-perfect-solution sell. If we only love our children hard enough, problems will miraculously vanish. The "scenarios" presented are patently ridiculous: children are instantly repentant and apparently change their ways when presented with loving correction.
Third, the book fails to mention that there might be something actually wrong with your child. Every parenting book should include, regularly throughout the book, that if your child doesn't respond within a few weeks, that you should request a referral or further medical observation.
For example: "The mishandling of anger is related to every present and future problem your child may have-- from poor grades to damaged relationships to possible suicide... Most of life's problems will be averted and your child will be more able to use anger to his advantage, rather than have it work against him" (p. 160). It is my uneducated opinion as his parent that my child's problems are almost exclusively related to his anxiety, his ADHD, his hearing deficiency, and his vision problems. All of these affect his schooling to a much greater degree.
If this book is to be of any value, it would be to first-time parents of very young children who are expected to be neurotypical.