I had the privilege of reading an Advanced Reading Copy of The Power of a Whisper by Bill Hybels courtesy of Zondervan. I didn't know what to expect going in as I have never read any of the writings of the Willow Creek founder.
Overall, it was a good book but really wasn't necessarily suited for me. That however does not mean that it isn't worth reading, but for someone who was a Religion major in undergrad and then went on to Seminary it just didn't bring anything great to the table for my tastes. Personally, I would have found it more interesting if it was just a straight narrative piece that talked about the way God had "whispered" to Bill and how his responses (either listening or ignoring) ended up changing his life (for good or bad). Now, those components are in there, but they are inter-twined with practical advice, etc. This book is great for newer Christians or those who have remained "surface level" but are now going deeper and that is who the book seems to be directed toward. In that regard this is a great book because you get to enter into Bill's reflections on how God has whispered in his life, but also see how he lives out a life attempting to hear the voice of God.
The best part of the book is probably the fourth chapter where it talks about how one can discern whether a whisper is from God or not. Bill shares five "filters" that he uses to help him discern whether a prompting is from God or something of his own mind/desires.
#1- Is the Prompting Truly from God - take time to reflect and ask again
#2- The Scripture Filter - Does it match themes in Scripture
#3 - The General-Wisdom Test - Does it go against wisdom and common sense?
#4- The Wiring Test - Does it match background, gifts, education? This doesn't rule out the possibility of extreme change, but points to if it is a 180 there probably should be multiple affirmations of it.
#5- The Godly Counsel Test - Run it by Christ-followers who are mature in their faith.
This is probably why I think this book is best for newer Christians or those who are now going deeper. It is a great guide to helping discern how God might be prompting individuals in their life and gives some narration of how Hybels has interacted with God's "whispers" in his own life.