I have a twofold response here.
Atheists who are interested in gathering the social benefits of church attendance without checking their brains at the door might want to look at the Unitarian Universalist church, which has no dogma. I mean it. They have no dogma. In theory this means there's absolutely no inherent contradiction in the idea of an atheist Unitarian. You're a Unitarian if you sign the book saying you're a Unitarian: what you believe is entirely up to you. In practice, the degree to which an atheist would feel comfortable depends a lot on the local UU congregation. Some are essentially liberal Protestant churches with some handwaving of the thornier bits. Some actively welcome atheist members.
I think the social aspect is critically important to an understanding of why people continue to seek out religion after the Enlightenment, but I don't think it tells the whole story. I think there's good evidence that spiritual experience--and here I am not talking about sitting on a pew on Sundays and mouthing hymns, but rather about the real deal, a mystic state of religious transport and ecstacy--boils down to chemicals in the brain. I believe this because there are drugs like ayahuasca that trigger these experiences very reliably. It looks to me that every human culture has its own way of reaching this brain-state: it very often centers on music and dance, but meditation, self-hypnosis, yoga-like practices, or an endorphin rush triggered by fasting and self-harm are all common as well.
Some brains reach this state more easily than others. Some brains absolutely crave it. Some are all but immune to it. This is why some people become shamans, or religious nuts, and some don't. Authentic ecstactic experience is (or was, until people like Alexander Shulgin came around) comparatively rare, but even when people had one such experience in a lifetime it was enough to change the course of civilizations.
I also strongly suspect that the state of "creative flow" reported by artists--the state where the artist feels that s/he is merely "taking dictation" from a higher power--is chemically similar to the state of religious ecstacy. There's too much crossover between the message that artists and mystics "bring back"--a general sense of oneness, higher purpose, the interconnectedness of all things, etc--for this not to be true. I also, based on my own experience, suspect that the state of flow experienced by programmers is not too far off. That state when you're holding all the connections in your mind, and you see the way forward, and you're like a god--yeah. That one. Except about a thousand times more significant.
Where I think the proselytizing atheists tend to go wrong is that they discount the power of that brain-state. I mean, part of it is that it's by definition charged with meaning. So naturally it's going to feel like the Most Important Thing Ever. You're flooded with a sense of immense meaning as part of the experience itself.
And I also think that the experience is desirable. Everyone should get to have it at least once. It clarified a lot of things for me in my early twenties. Religious practice gives people--oh, the lightest shade of what a true ecstactic moment has to offer, but for the kinds of brains that crave that state, religious practice is really important to their ongoing sense of well-being.
I think in a way the proselytizing atheists are being chemically...discriminatory? That's not exactly right, but they're failing to recognize that some brains crave an experience their own brains do not. They're trying to other-optimize without fully understanding all the benefits that religious practice provides to the people who are so emotionally attached to it.
Some [UU churches] actively welcome atheist members.
I visited the uucpa once. Fifty people or so gathered in a room to sing songs for an hour; someone lit a flame, and rang a bell; and a congressperson gave a sermon on the health care reform bill. Afterwards, we went out for brunch. There is a humanist reading group as well.
I can see how an atheist would be comfortable there. It didn't personally excite me, though.
In the comments of a recent thread, another poster pointed out that religious individuals tend to report higher levels of happiness than nonreligious individuals. I suggested that the social network of churches, rather than the direct effects of theistic belief, might be responsible for this difference, and after doing a bit of searching around to see if the available studies support such an explanation, found a study that indicates that this is indeed the case.
Religious churches may be far from optimal in the services they provide to communities, but they have a great positive impact on the lives of many individuals. And not just as friendly social gatherings and occasional providers of community service; I've known priests who were superb community organizers and motivational speakers, who played an important role for their congregations to which I know of no existing secular analogue.
It seems probable that a secular organization could effectively play the same role in a community, but would anyone be likely to take it seriously? Since people who're already religious may be inclined to reject the value of a secular authority filling the role of a church, and atheistic individuals may not be inclined to attend, either due to reversing the stupidity of religion, or due to asocial and anticooperative values, it's uncertain whether a secular organization that adequately filled the role of a church would get off the ground in the first place in the present social climate.
So, what are your feelings on the prospect of secular church analogues? Do you think that they're appropriate or practical? Do you expect them ever to become common in real life?