I realize the analogy doesn't perfectly map. Having rare crazy beliefs is a bigger red flag than having common crazy beliefs.
Also, a religion has features that greatly appeal to people in a way country club membership does not and these features may lead people to become or remain members despite disagreeing with the religion's social policy. Plus, though I don't particularly like defending the Catholic church, they don't refuse membership to homosexuals or revoke the membership of couples who use birth control.
I tried to make the country club a version of the Catholic church that was nicer in every way. Instead of claiming you will be tortured forever if you do those things (and don't go to confession), the country club asks you to leave.
Let's say you are interviewing a candidate for a job. In casual conversation, the candidate mentions that he is a member of a rather old and prestigious country club. You've never heard the name of the club before.
You look up the country club afterwards, and are surprised by what you read. The club refuses membership to homosexuals. It revokes the membership of couples who use birth control. Leadership positions are reserved to unmarried males.
The candidate is otherwise competent. Under what conditions would you hire him? Would you want a law passed banning hiring discrimination based on country club membership?
(The country club is analogous to a nicer version of the Catholic church. I left out a couple bad things.)
Religious discrimination is illegal in many parts of the world, and I think that's probably a good thing. Still, keeping this at the object level (no meta-rules or veils of ignorance) it seems to me that discriminating against religious people is fine. I'm curious what other people think.