I am sorry...Christianity branches off from Judaism does it not? Christianity itself isn't exactly up to its ears in metaphysical battles in its own New Testament either....and that's not escaping the point that it wasn't me who brought it into this discussion in the first place. It's a default insofar as it is a term used, out there, in wider, non Trek fan society. It's the default for American Hollywood productions to a certain extent too, with the dominant, or at least most powerful, religions in the United States and particularly Hollywood, being either Judaism or Christianity. With differing levels of orthodoxy or denomination or sect of course.
It may well have its roots in WWI and the enmity with the Ottoman Empire, but that doesn't stop it being a word that people use. You may think it's lazily slammed together, but the rest of the world doesn't seem to, and given how one of those religions branches off from the other, it's hard to say it is incorrect. You can nag it for not including other Abrahamic faiths, but that's about it.
Trust me, I am quite familiar with both Judaism and Christianity, and a fair amount with Islam. Us young metropolitan folk in the UK become better than some diplomats by the time we all sit down for a kebab together in secondary school, and you can throw in some Sikhs, Hindus, maybe a Buddhist or two and an Atheist for accuracy at that table.
So...calm down. We are discussing Bajoran religion as an offshoot of discussing Kiras position in it. That included talking about real world religions as parallels. Kira basically went off to be space Pope. Someone said they felt Bajoran religion went too Judeo Christian, but some of us don't think that's the case.