This is a very specific (but, unfortunately, common) scenario where that type of "Christian" is demanding that secular law conform to their delusions of theocratic supremacy.

They aren't necessarily choosing to subscribe to the belief that there is only one supreme deity. For many of them, that's simply a belief that makes the most sense to them. They are, however, choosing to use their religious identity as a pretense for exploiting and subjegating others. That's based on the nonsencial notion that their Christianity, in and of itself, somehow makes them superior.

This is the key difference. You are saying that religious belief "should never be enough to privilege anyone." And you're right. It shouldn't be. But we can't conflate what "should be" with what "is." Clearly, our society shows distinct privilege to people with Christian -- or, more generally, monotheistic -- beliefs. Privilege isn't something that *should* become the basis for one's values or their morality (or lack thereof)...but it does.

Since your husband was atheistic or agnostic when it came to views on religion/irreligion, it sounds as though you're describing how he was accepted as culturally Jewish amongst others who practice Judaism. But he obviously differed from practictioners of the Hebrew faith who blatantly subscribe to monotheism. Many Reform, Conservative, and Orthodox Jews clearly would consider themselves to be monotheistic.