I’m often asked by theists I meet, particularly evangelicals proselytizing at the local library I visit, why I’m not a theist, or more specifically, why I’m not a Christian. There are several reasons for this, but a few stand out:
First, like Bertrand Russell, I simply have learned too much to find any of the Christian dogmas credible, particularly the fundamentalist notion of Biblical inerrancy — I’m quite aware that the Bible has been repeatedly edited, reedited, censored, and “updated” many times over the centuries by theological and political opportunists, which would not be the case if the book were truly a perfect work written or inspired (whatever that’s supposed to mean) by an all-knowing God who you think could write a book, well, perfectly.
Second, even considering Christianity alone, some sources have estimated the existence some 30,000 Christian sects, churches and denominations, many of which do not even consider others to be Christian! Each claims the Truth™ for itself, at least implicitly, and there’s no objective way to tell which one is correct, which one to choose. After all, no matter which one is chosen, you still go to hell according to the devout believers of all the others for choosing the “wrong” religion.
Third, being “saved” does not interest me — WHAT MADNESS IS THIS????? — because I know just enough about psychology and neuroscience to strongly suspect that souls and ensoulment do not actually exist or occur. Couple that with a strong suspicion of the nonexistence of any divine agency to do the saving, from hell or whatever, and I have what I consider good reasons indeed not to engage in theism.
Non-Christian religions, as interesting as they are, aren’t much better, and no religion has ever had a plausible way of convincingly showing it’s claims true to a critical and knowledgeable nonbeliever, causing further problems for the credibility of any religious belief system or invocations of Pascal’s wager.
This is why I’m a nontheist, and will likely remain one of full conviction to my deathbed, though I could be wrong…