This is the book that started a movement in the church local and global to call God's people back to orthodoxy and orthopraxy in the area of adoption, both earthly and heavenly.
I have no doubt that I will look back at the end of my life and see this book as one of the most influential I read. You may think that you only need to read this book if you are considering adoption. You would be wrong.
While the entire book is wonderful, I believe the most helpful portion is not the practical wisdom given about earthly adoption. It is the more foundational section at the beginning about the theology of adoption and its implications for God's children. After reading this section I share Moore's conviction that the doctrine of adoption has been severely neglected in the modern church.
This book has been amply reviewed by both Mark and Ron here and here. Seeing these men strive to be faithful to the truths the Gospel as laid out in this book over the past few years has been a great encouragement to me.
This book will change you and change how you see your Heavenly Father. Read it.