This is exactly correct. And another way to put it is that "religion is the set of core assumptions that a person uses to formulate all of their other beliefs".

I think it's crucial that more people start to realize this, because once we realize it, then it becomes obvious that the "freedom of religion" established by the First Amendment is in fact totally impracticable and bound to produce legal paradoxes and inconsistencies.

And so ultimately, what we need to do, is abolish the "freedom of religion" established in the First Amendment, and replace it with the more generic, but also more precise and logical "Freedom to do and think as you please, as long as it doesn't conflict with other peoples' right to pursue happiness".

I actually published an article about this yesterday: Freedom of religion was a bad idea all along: https://medium.com/@nebulasaurus/freedom-of-religion-was-a-bad-idea-all-along-f236181db33c