That depends, as the comment you replied to shows, on how they respond to that. I'm an atheist, but one of my wife's best friends is a dyed-in-the wool catholic, and we get on really well despite that fundamental difference. He has a great line in self-deprecating humour, where he talked about "going Taliban" during lent, of which he is very observant. Not all religious people - and, I would suggest, probably very few in fact - are nutters. They're just the loudest ones.

I thought so too, until I realized that if atheists see God as a deep aspect of the human mind, that evolved that way for reasons, then we don't miss much of the Judeo-Christian story. I stopped by a local church for Bible study just in order to challenge my assumptions and found that they had no problem with that formulation at all. I expected way more awkwardness and even pushed the issue, to no avail. The result was a delightful experience of people sitting around interrogating ancient texts and being attentive to each other's life challenges.

I found that the structure of the Christian congregation is equivalent to the anarchist affinity group. I realized that, unlike us, Christians build infrastructure to support their organizing, and we should probably adopt that.

I'm still the same atheist, just a churchgoing one. I don't go to mass often or ever recite the Nicene Creed, but otherwise it's been a fantastic social outlet, great intellectual company, and the organ festival is off the hook.

Yes and no, if you join a group that is not overzealous you can just skip the religion talk altogether and involve with community projects instead.