Better Together: What on Earth are we here for? by Rick Warren
We used this book in our church small groups. For the second year everyone was invited to do the same study and this was the study during Lent. It was a good book, definitely a group book, not something you'd want to do on your own. I liked the small group. I enjoyed most aspects of the book. I did disagree with one point the first week, but other than that I do recommend the book in a group setting.