It's a fantastic book. I loved it as I was reading it even in earlier drafts, and I have been anticipating its publication for a long time. You'll all want a copy, trust me. Buy it and read it. And if you like it, give it a customer review on Amazon, critical or laudatory. We'll need honest Amazon reviews to counter the inevitable Christian tactic of low-starring it and lying about it to dissuade fellow Christians from reading it. I'd rather have valid criticisms in there if any.
Following is a summary of the book, then at the bottom a link to a companion website for the book that actually has new additional articles by me and others (check it out!).
Two of The Christian Delusion's fifteen chapters are mine. The first is Why the Resurrection Is Unbelievable, which is the most definitive refutation of warranted belief in the resurrection I have ever composed. It's a deliberate tour de force, such that I doubt I'll ever have to write another. It even takes down recent attempts to use Bayes' Theorem to argue for the resurrection, and it contextualizes everything so there just isn't any rational basis left for claiming the resurrection is historically proven.
The second is Christianity Was Not Responsible for Modern Science, which is another tour de force, conclusively taking down once and for all the claim that Christianity gave us modern science. If you didn't know Christians were arguing that, I give numerous quotes and citations. I expose their logical fallacies and factual errors, which are so egregious you'll agree advocates of the thesis must be delusional. My debunking of it is so decisive in this chapter, you won't need to refer anyone anywhere else.
I provided some editing assistance and peer review for TCD, so I can vouch for it all. John and I wanted this book to be conclusive, every chapter its own tour de force on each topic. And we achieved that goal. The book is superb. Every chapter is fantastic, some more than others, but all are great. It doesn't cover every subject it could have, but the subjects it does cover it covers thoroughly, leaving nowhere left to run. It's all readable (nothing will be above anyone's head). Much of it will even be fresh and new to you (and that's saying something).
Most of all, taken together, its fifteen chapters are sufficient to establish that Christianity is a delusion. The Christian religion is so manifestly contrary to the facts, belief in it can only be held with the most delusional gerrymandering imaginable. That's a bold statement. I wouldn't have made it myself before reading this book, but now that I have seen it all in one place, I am forced to agree. Richard Dawkins was often criticized for dismissing "The God Delusion" on shallow arguments that didn't address common Christian "rebuttals." The Christian Delusion was specifically constructed to leave no such excuse.
The first four chapters alone are priceless, covering the psychology and cognitive science of human error, demonstrating that religious belief can only be maintained by relying on common causes of error, rather than correcting for them. Two chapters on this are by Dr. Valerie Tarico and Dr. Jason Long, and I learned a lot from them. At the same time, Dr. David Eller (an expert in the anthropology of religion) exposes how Christian missionaries use the science of anthropology to market the gospel in other cultures, and how they acknowledge how culturally relative religion is, even their own religion, yet irrationally fail to see how this actually makes their religion no more credible than the ones they seek to displace. John Loftus contextualizes all of this by reiterating and defending his Outsider Test for Faith, which has been widely hailed as a devastating new argument against religion, and here he confirms its reputation. It's the lynch pin of the whole book, the fulcrum on which every other chapter does Christianity in.
Ed Babinski follows with a chapter proving the Old Testament assumes a flat-earth, three-tiered cosmology that everyone now agrees is wholly contrary to the actual physical facts. If the Bible can't even get that right, it can't be the inspired word of God. And if it isn't the inspired word of God, Christianity can't be true, because Christianity only makes sense in the context of the system of theology and salvation constructed in the Old Testament. Indeed, since the New Testament outright says that (where even Jesus quotes the Old Testament as the inspired word of God), disproving the OT proves the NT is just as much in error.
Supporting that point is a chapter by Paul Tobin surveying some of the most egregious things mainstream scholars all agree is wrong with the OT and NT ("it is inconsistent with itself, is not supported by archaeology, contains fairy tales [and] failed prophecies [and] many forgeries"), and though you might have heard all that before, seeing such a succinct summary of it hammers home its significance. We can't let these things slide anymore. Because they disprove Christianity. Point blank. Excuses won't fly.
John Loftus caps the point with a chapter establishing that, indeed, excuses won't fly. We've all made the argument in casual conversation that making excuses for how the Bible says one thing but is supposed to mean another (the stock tactic employed by the delusional to maintain their belief that it's all divinely inspired and was endorsed by a perfect God) only proves that God is an incompetent communicator, and therefore not perfect (in fact, he'd have to be substantially retarded by the standards of even average human communicators). Loftus doesn't just say this. He proves it.
Next are two chapters proving the Old Testament God is evil. And both do so in a novel way. So if you think you've heard it all before, you'll love these. First Dr. Hector Avalos eviscerates Paul Copan, exposing his incompetence and delusional distortion of the facts in his already-absurd attempt to justify genocide and every other unconscionable brutality as 'alright if God says so'. You heard that right. The new Christian tactic now is not to deny that God commanded evil, horrible things, but to argue that evil, horrible things are okay. Well, good luck with that marketing strategy. Christianity is doomed if that's all they've got now. Avalos further shows how unremarkable the Old Testament laws are in their cultural context, no better or worse than (and suspiciously very much the same as) the manmade laws of surrounding civilizations, dispelling any belief that the OT was inspired by anything but ordinary, ignorant human beings.
John Loftus carries the point home with a more philosophical point: that vast and widespread animal suffering is so unconscionable if theism is true, its existence entails God is evil (or, of course, doesn't exist). This was one of the funniest chapters for me, because I never knew all the squirmy ways Christian apologists have actually tried to get out of this argument. Loftus digs up the most amazing apologetics, and eviscerates them all. You'll be amazed at how desperate the explanations are. You'll be amazed Christians have even realized it's a problem. And a problem it is. A big problem. And as Loftus proves, an insoluble problem. Christianity essentially falls on this argument alone.
The next section takes on Jesus. My least favorite chapter is by Dr. Robert Price, essentially a take-to-task pointing up the invalid leaps of faith disguised as objective reasoning in the recent Boyd and Eddy apologetic text The Jesus Legend. Not that he's wrong about them, indeed he is amusingly correct on every point. It's just not the slam dunk, tour de force the other chapters are, and I fear some readers will not understand the context of many of the things Price talks about (though reading his book would help). Nevertheless, it's only the worst of the best. Which means, still pretty darned good.
My chapter on the resurrection follows, and then the slam dunk of them all: John Loftus presents the "Duh!" argument that the Gospel Jesus (and insofar as we can honestly claim to know, the actual historical Jesus) issued prophecies that didn't come true. Which means he was a false prophet. Which entails Christianity is false. Done and dusted. The horns impale any attempt at escape: either the New Testament is full of error (and we cannot trust that Christianity is true on the word of such a wildly erroneous book), or Jesus was a false prophet (and Christianity is thereby refuted). Either way, Christianity falls. The only conceivable escape is back into the "God didn't mean that" fiasco, but then you get impaled on Loftus' earlier chapter. No way out.
The book concludes with examples of particular recent Christian delusions: that morality comes from Christianity (Dr. David Eller refutes that notion, and though he is a relativist and we disagree on the philosophical warrants for moral belief, everything else he says is spot on); that Hitler was an atheist and the holocaust is the legacy of atheism (Dr. Hector Avalos provides the most devastating refutation of this claim ever published, alone worth the price of this book; his tabulated comparison of Charles Darwin and Martin Luther may be the funniest thing ever); and that Christianity was essential to developing modern science (my chapter, summarized earlier). These delusions aren't required to be a Christian, but they illustrate how prone to delusions Christians are.
There is a companion website well worth bookmarking and exploring, where critics of this book will be responded to by the authors, and which right now has information about all the authors and contents of the book, a copy of the introductory chapter, praise for the book by over a dozen renowned experts (atheist and Christian alike), and several bonus chapters that didn't make it into the final edition for lack of space to include them.
Two of those are written by me: The Will of God presents twenty four verses from the Old Testament that damn the book as so viciously immoral no sane, humane being could ever endorse it as God's word (which would have gone into Part 3: Why the Christian God Is Not Perfectly Good); and Christianity Was Not Responsible for American Democracy demonstrates that the U.S. Constitution was not based on Biblical principles at all, much less the Ten Commandments, and that it has far more to do with ancient pagan political philosophy (which would have gone into Part 5: Why Society Does Not Depend on Christian Faith). The latter is very much a companion piece to my chapter in the book on the origins of modern science, representing instead the origins of modern democracy.
Prometheus Books screws over its authors. Loftus tells me they shafted him with a 2.5% royalty...no, that's not a typo (industry standard is 7.5%). They've done this to other authors I know. And a lot else that annoys me. So I'm not a fan of PB. But I believe in supporting authors, and the cause of knowledge and reason. So please buy this book. If you love it, buy more and give them to friends and libraries. The better it sells, the more attention it will get, and thus the more influence it will have. John and I are planning a sequel that will expand on this with even better material; but we'll be pitching it to another publisher, and great sales of TCD will help win them over. But read it first and decide for yourself.
[Update 2011: for a good summary of The Christian Delusion and how effective its chapters are in conjunction see my entertaining Skepticon talk Are Christians Delusional?]