This is the follow up to his Christless Christianity which is a terrific read and an important book (R. C. Sproul's review is here).
The goal of this book is to reorient our faith and practice as Christians and churches toward the gospel: that is, the announcement of God's victory over sin and death in his Son, Jesus Christ. The first six chapters explore that breaking news from heaven, while the rest of the book focuses on the kind of community that this gospel generates in our world. It is not merely that there is a gospel and then a community of people who believe it; the gospel creates the kind of community that is even now an imperfect preview of the kingdom's marriage feast that awaits us.Sample pages are available here.
(HT: Justin Taylor)