Rule #3: Learn about Buddhism
I’m not saying that you need to become a Buddhist or start meditating, but you should at least know something about Buddhism, because Buddhism is easily the world’s most well-known and popular atheistic religion.
Yes, that’s right: Buddhism has no deities. The Buddha himself was considered a philosopher and teacher, not a god. That’s not to say it doesn’t have any scientifically unsound beliefs (there’s really no logic behind Nirvana), but it definitely does not have deities.
This is important to know because Christians tend to be locked into a mindset which says that there are basically two choices in life: religion (by which they mean “a religion like mine”) and atheism. The idea of a well-known and respected atheistic religion is a bit of a mind-blower to them; most Christians think that Buddha is just an eastern version of Jesus.
Pointing out the existence of a respected atheistic religion throws a bit of a wrench into their thinking, and may help deflect the inevitable accusation that atheists either have no morality or are all Communists. Of course, there are logical ways to refute those assumptions, but human beings are not very logical creatures. I find that it works better to approach them from the standpoint of a rival religion than no religion at all, if they’re the type who are willing to listen at all.