Amos is correct.

You can't have human sacrifices - but only because all of the people, regardless of their religious belief, are prohibited from committing murder.

You can't slaughter animals (in most cases) because that violates both health laws and animal cruelty laws that apply to all of the people, regardless of their religious belief.

You can't force anyone to marry against their will, because slavery is prohibited for everybody.

You can't smoke that funny stuff and chaw on them fungi in your rituals because -- oops, I think there's an exemption there (for some religions). [We gotta look at whether that's fair to the rest of us.]

John