Disclaimer: I haven't read Witherington's books; quotations from them indicate to me that he has some notions with which I'd heartily and emphatically disagree.
HSAT: Justin Taylor links to a first and second post by scholar Ben Witherington, offering a withering (pun intended) interaction with Barna and Viola's Pagan Christianity.
You don't have to have read PC or any of Witherington's books to find this pair of essays profitable. Witherington offers some very solid, Biblical, historical, theological interaction with an idea that's been festering for a few decades. This is the idea that what's really wrong with the church is that we have structure in our services, meet in buildings, and have services led by men. Things would be so much more wonderful if we had none of those things. Constantine ruined everything. All those bad things entered after several centuries.
Witherington points out that the idea is itself nonsense: those unstructured meetings still meet in particular places at particular times with particular ends in mind, and have particular individuals exercizing some sort of oversight. But he also shows the bad, un-Biblical thinking that lies at the bottom, and the crazy (I'd say Dathanic) abuse of the truth of the priesthood of all believers.
(Anyone over 40, I'd say, looks at the current Emerg*** [and other] mish-mash and thinking, "Uh, yeah, this is so new we already tried it and rejected it in the 60's and 70's.")
Witherington offers more, but you'll find here a bracing and healthy counter to this latest man-centered fad. It's well worth wading through, and not minding the typo's.