One important difference between being religious and being an atheist is that religions often have strict instructions about specific behavior. A religion, for example, may have a rule forbidding participation (or even silent assent) in a prayer to a different deity. Atheism, on the other hand, doesn’t carry any specific moral commands (note to obnoxious Christians: this does *not* mean atheists don’t have any morality, merely that they don’t have some centralized dogma).
While some may say that going along with a public prayer (by bowing one’s head and/or even reciting the words) is dishonest, and therefore immoral, it’s at least a debatable proposition. And since atheism doesn’t inherently have any centralized moral dogma (even the notion that dishonesty is wrong isn’t necessarily implied by the mere non-existence of deities), it’s not quite as clear-cut how to behave in a given situation.
Another difference is in the area of evangelism. Many religions (notably Christianity and Islam) command their followers to reach out to convert nonbelievers. Atheism, of course, does not. It may well be the case that truth is better than falsehood and knowledge is better than ignorance (I certainly believe that), but there’s nothing about atheism per se that commands atheists to reach out to convert (or de-convert) non-atheists to atheism.
Likewise, many religions command or encourage their followers to acknowledge their deity publicly. That creates a potentially asymmetrical sitation — when a Christian or Muslim injects their religious views into a conversation (or just makes a religious gesture after scoring a touchdown or something), it can be argued that etiquette dictates we cut them some slack, since they’re caught between a God and a hard place — they’re being a bit impolite because they’re following what they believe to be a divine command from a deity they worship. On the other hand, an atheist who injects their non-belief into a public situation doesn’t have the fallback of claiming they were just doing what God commanded them.
Is this fair? Of course not. But if you’re an atheist, you don’t have any innate reason to expect that life would be fair (and therefore, perhaps, more motivation to work to make it more fair when possible). Does this mean an atheist has no moral basis for asserting that there aren’t any deities, or pointing out the various flaws in religious people’s beliefs? No, but it does mean it’s harder to claim you feel a burning need to spread the word about your worldview.
My advice: If you want to call out an obnoxious believer on how silly their beliefs are, make sure that 1) they’re coming off as obnoxious to the other folks around, not just to you; and 2) the beliefs you castigate as silly are specific to the obnoxious jerk, and not shared by the rest of the folks.
In other words, if the obnoxious guy is a fundamentalist, and you’re pretty sure the other folks aren’t, then go ahead and point out some direct contradiction in the Bible, and watch them squirm.
But if you point out how silly you think it is to believe in a deity in the first place, you’re likely to alienate the onlookers and turn your opponent from an antagonist getting well-deserved comeuppance into a victim being bullied.
(cartoon via Swenson Funnies)