I have no issue saying I think religion is BS. I don't care if I lose friends over that tbh.
I just don't normally do so because a) it won't change their mind and b) I don't care what they believe. I still think it's crazy but that's fine. Everyone is a bit crazy anyway. And c) I prefer focusing on common ground than contradictions.
But tribes are overrated in this day and age. If you don't fit in you can just find another one that you do gel with. This changes over time too.