DeYoung's philosophy is simple, "Live for God. Obey the Scriptures. Think of others before yourself. Be holy. Love Jesus. And as you do these things, do whatever else you like, with whomever you like, wherever you like, and you'll be walking in the will of God.
It is sad that DeYoung's approach will come as novel to many readers. But it is not. This approach is certainly as old as Augustine who essentially said, "Love God and do what you want". Much of this book is given to tearing down the "hyper-spiritual approaches" that don't work. DeYoung also offers some instruction as to what to do--but if you are looking for magical answers you will not find it. His advice is simple--just do something.
This book is well written and extremely helpful. If you are the type that is constantly wondering what God's will is, then you need to buy this book. If you work with teenagers or thirty-somethings that are still looking for direction then buy this book. If you have an adult living in your basement that should have a job, be married, and not living in your basement then perhaps you should slip it in front of their Xbox 360 with a note that says, "Read this!!!"