Joining a group that believes in magical sky dwelling beings that grant eternal life in utopia provided you worship them enough isn’t the only path to community and purpose.
Whether by force/dogma or voluntary, a uniformly religious community connects at least weekly and includes all. Through this meeting, you get to know pretty much everybody, what they do, their families, their businesses. Which serves as a platform for making friends, finding partners, business opportunities, the like.
For the time/effort needed to join this community (plural), its pretty much free, maintenance isn't all that much either. People a few hundred years ago already did the hard part.
Not a bad deal. And all you have to do is suspend a little disbelief in something for a while.