No, it isn't about who you talk to while getting a blow job, though that is also an interesting question. It's about how you can talk honestly about religion to believers without offending their delicate little sensibilities.
The question occurred to me as I was browsing Amazon looking at books about atheism. One complaint that arose repeatedly about all the books was that they were intolerant or bigoted or narrow-minded or smugly superior or otherwise just not nice about religious belief or about believers. There's no question that some of the books--anything with Christopher Hitchens associated with it, for instance--are calculated to offend. On the other hand, some of them were works based on reason and philosophical principles, and relatively dispassionate. But even for those, here's the problem. Let's say you really think (and can cogently argue) that there is no reason to believe in a big man in the sky (a la any mainstream religion) or anything like him, and the various reasons adduced to support such a belief appear to be weak or non-existent. And it's apparent that such belief isn't really adequate for a consideration of the modern world. And so on.
What ends up happening is that religious ideas and the credulous impulse itself almost inevitably have to be described in terms that are less than flattering, even when not used as invective. Let's face it, when discussing actual religious substance and you point out to an adult that he's using the same kind of faulty reasoning as a small child, or that his arguments in favor of God's existence (or the possibility thereof) apply equally well to unicorns, or whatever, it's understandable that they get a little tweaked. But what are you supposed to do? Pull your punches?
This sort of leads in to the whole "everybody needs to respect everybody else's belief" thing. I'm sorry, there are cases where that's just not possible. I can respect and would even defend anybody's right to believe as they wish, but there's just no way I can respect a belief and line of reasoning that isn't, well, respectable. Even people who make the plea don't really buy it, or at least I hope not. Let's get real here. If while discussing religion at a cocktail party some fellow, his tongue loosened by the third martini, professed a literal belief in the ancient Egyptian or Greco-Roman gods, would anybody feel required to validate such nonsense by honestly allowing as how that's a perfectly reasonable thing to believe, and by golly, though it's not how I see things, you know, it just might be true. Other than for the sake of politeness and bonhomie, I sure hope not. Zeus is dead, people, and as far as I'm concerned, so is the god of the desert religions. (The rest of them, too. Call it a theoholocaust.)
Now, if you're having a real honest discussion with a Baptist about what they believe, is their false belief system and the incredibly faulty edifice upon which its built due more respect than that of the hypothetical cocktail party guest just because a lot more people go to church on Sunday than make sacrifices at the Temple of Apollo? I just haven't got it in me to nod pleasantly and say, "Well, though I'm not a person of faith myself, believing in the Christian theology is nonetheless a perfectly reasonable viewpoint." Sorry, it's not reasonable at all.
I dunno. When dealing with the honest and well-meaning theists, I just try to be as nice as I can, tell the truth without rancor, and let the chips fall where they may. Still, there ought to be a better way. Any ideas?