One of the things that brought me over to the atheist / skeptic position I now hold was the discussions that took place long ago in the Why Won’t God Heal Amputees? forum. Why Won’t God Heal Amputees is a website that centers around a book written on belief and non-belief. My experience was that I had seen a video about the website’s arguments that god was delusional, so, as a Christian, I set out to write a refutation of what was being said. The webmaster posted my refutation in the forum, and there I began to discuss with the unbelievers what my thoughts were, and why I believed what I did. Although the website did not convince me (in fact, I still think that some of Brain’s arguments are unconvincing and don’t offer much that a really sophisticated Christian would find all kinds of reasons to reject), it is certainly true the conversations I had on the forum did influence me towards my present position.
Now Marshall Brain has released a revised version, now in print, called How “God” Works. I browsed through it at the bookstore, and I think it’s overall a nice addition to the atheist library (If you want to get a feel for how Brain argues, read this or this). Brain’s approach is very common-sense and written in plain language. Indeed, he has done a masterful job of explaining why God is imaginary in the same terms that a children’s author might use to explain why there’s no tooth fairy. Even if he misses the mark every now and then (like taking Jesus’ statement “nothing shall be impossible to you” a little too literally) I’d say that most of his concerns are totally valid. For example, it is true that people have invented all kinds of gods throughout history, and the known human tendency to invent gods is grounds for doubting Yahweh. It is also true that we do not have any kind of direct physical evidence of a god, even though such might be expected if God existed (Couldn’t we have had a holy book filled with scientific knowledge beyond the people of the time, very specific and fulfilled prophecies, etc.).
There is certainly a place for this: just like the teaching of Biology and Economics is taught in graded levels of depth and complexity to high school students, college freshmen, and doctoral candidates (high schoolers are taught these subjects in very simple terms while doctoral candidates taught in very complex terms, and college freshman given a level of understanding somewhere in the middle), likewise it is necessary for critical thought about religion to be taught at the simple level (How “God” Works) the intermediate level (my own book Atheism and Naturalism fills this gap out nicely!) and at the complex level (Graham Oppy’s Arguing About Gods).
I know what it is like from personal experience to lose a belief, and it can be rather difficult to find your way out of the maze. Even as you open your eyes to the glaring problems with Christianity, Christianity tends to keep a hold on people because they often think that there beliefs are supported indisputably by hundreds of different things (what about all those Bible prophecies that my pastor told me about? what about those confirmed scientific facts of the bible that I heard about in sunday school? etc. etc.). It’s easy to see how even a pretty rational person might not make all the way out of belief, because he might be in the position of feeling like there are both reasons to believe in Christianity and reasons to disbelieve it. Faced with such a situation, that person might err on the side of caution by continuing to believe (I don’t want to go to hell!), or reason that the “if Christianity is false, it’s hard to see how there’d be evidence that was right, but if Christianity is true, it’s perfectly conceivable that there might be some things we don’t understand.” Few people undertake the effort to re-examine all those old reasons. If they did, they would find one by one that all of these incredible proofs of Christianity crumble to dust. I go over claims of prophecies and Christian apologetic arguments in my book, and talk.origins has refutations of tons of these type stories. So, a believer who wants to undertake the task of looking into all their old reasons for believing should definitely check out those resources.