Groeschel's "It" focuses on the difficult-to-define thing that some churches just seem to have while others do not have it. "It," as he calls it, is something you cannot clearly illuminate but he does a great job of posing key questions to help a church define whether it has "it," how it might get "it," and how a church can lose "it."
One thing that became very clear as I read this book, though, was that "it" applies to much more than just churches. If you run or lead any sort of organization, business, or ministry, this book will be full of thought-provoking moments for you ... moments that will cause you to think and scratch your head, and go back and make some changes in the way you do things.
I highly recommend this book for any leader. It is also a very fun book to read, with my sidebars and stories as well as Groeschel's trademark sense of humor.