This book gave me the rare experience of having a large gap in my knowledge completely filled, like a jigsaw puzzle piece fitting perfectly into place. It was as if what were only dim intuitions and questions in my mind were laid out and clearly explained, answered, and connected. It's also rare that such an explanatory book could also be practical, and in parts, moving and inspiring. I esp. appreciate the quote from Brother Lawrence: "People would be surprised what the soul sometimes says to God."
I used to be very dubious about statements such as "everyone has addictions" or "most anything can become addictive." I know better now. Whether its hard drugs or most any repeated behavior--Are the patterns of neurological activity the same? Yes. Are the consequences for emotional and spiritual growth the same? Yes.
From an evangelical Christian perspective, May appears to be not 100% kosher, but it makes no practical difference in this book as far as I can tell.