I was raised Roman Catholic, had a Jesuit education, studied Philosophy and Religion as an undergraduate and had every intention of becoming a Jesuit priest. I am no longer Roman Catholic or Christian, but I am an active believer in another faith. I think that it's important to preface this question with that. If you have any questions about me in this context, message me, because I don't want this thread to go off topic.
Most American Christians of all denominations, from conservative Southern Baptists to liberal Episcopalians to Latin Mass attending Roman Catholics are fervent supporters of the First Amendment's establishment clause and the "separation of church and state" even though the way that they understand the application of that may be different from one another. This is something that disturbed me when I was a devout Christian and still confuses me as a non-Christian PhD researcher in Philosophy.
Nowhere in the Bible, the Creeds or Confessions or Catechisms of the major churches (like the Lutheran Book of Concord, the Anglican 39 Articles, the Reformed Heidelberg Confession, the Baptist Westminster Confession etc) is freedom for all religions and no religion affirmed, and in the Bible it is condemned in no uncertain terms, on several occasions. I can see why Christians would support freedom of worship for different Christian denominations for the sake of unity, but I can't understand how Christians defend the constitutional freedom to be a Satanist, a Wiccan, a neopagan, a Mormon or a secular humanist. What's the Christian basis for this? Please don't answer with a secular or legalistic argument, I know those very well. I'm asking how religious Christians justify that sort of thing through the lens of faith. I know that some Catholics will invoke Vatican II, but even Vatican II does not call other faiths equal or call for total toleration, just for ecumenicusm between Catholics, Eastern Orthodox, Protestants and Jews.
Me, I support a limited form of freedom of religion because my religion explicitly says that Christians and Jews, as the other two Abrahamic faiths, have a right to freely worship. That's my theological justification, beyond that I do not support the right of pagans or Mormons to worship freely, nor do I think that blasphemy against any of the Abrahamic religions should be treated as protected speech, because it is hate speech.
In the UK, where I'm currently a PhD candidate, there is an impetus within the Labour Party membership to bring back blasphemy laws as part of hate speech legislation, and I suspect that Jeremy Corbyn will support it, and that's a start, but I'm primarily talking about the United States in this comment, because there is no other country with a free speech/religion amendment to their constitution that is as irresponsible and broad as the First Amendment.
Thanks for your time.