OK - I just ordered Pagan Christianity by George Barna and Frank Viola. A friend told me about the book this week. Then, I just saw Greg Boyd's comment on it. Then, I went to amazon.com and saw a lot of comments from people I respect praising the book.
Greg says: "Viola, F. and G. Barna, Pagan Christianity (Tyndale 2008) is the best single source I know of that exposes how thoroughly pagan the traditional and contemporary understanding of the church is. Viola and Barna argue — rightly — that the passivity and impotence of the church today is largely due to this fact. Viola and Barna call us back to a New Testament understanding of church that is rooted in authentic communities in which believers share life and engage in ministry together."