The First Amendment in the US says — wisely — that we should avoid giving the government the power to determine with the force of law what beliefs are unacceptable. That is •not• because all beliefs are acceptable, however; it is because giving the government such power opens the floodgates of authoritarianism.
Here’s the thing: some beliefs •are• unacceptable. We deny the government the power to determine which ones with the understanding that we •must• do that job ourselves, through social negotiation.