The government should not have a role in determining what is the "right" religion. But neither should it have a role in telling us we MUST accept all religions
Prior to the 1960's or so, it was for private individuals to exclude offensive people. Business owners did not have to hire anybody they didn't like, and apartment owners didn't have to rent to people who they didn't like. It was possible to make offensive people feel very "unwelcome", without any government involvement.