The point is that the Authority, under the Guardian's leadership, is very invested in assimilation. Now, with the Exsanguination talk above, I think it's safe to say there's more to it, but for the purposes of this episode that is what they are about. Counter to them, in the established Vampire World, there are the -- sigh -- "Sanguinistas," who are fundamentalist terrorists convinced of the literal truth of vampire scripture.
Which is pretty sneaky, because you're talking about Al Qaeda but you're also talking about Creationism in the schools, but it's done in a dog whistle way such that your audience has three choices: See the parallels between Fundamentalisms of all kinds, see only the zealots of whoever they think is the crazy party, or just throw up their hands and say they were confused by this part. All valid responses, I guess. But what the show is doing is using the metaphor to explore the first one.
Fundamentalism, at its root, is about returning to a brighter, prior world which never actually existed. It's about taking the rules and the situation you would like to be true, and then pretending that somewhere back along a twisted path, before everybody got so out of hand, those things were realities. The Sanguinistas, Al Qaeda and Christian Fundamentalists all operate this way, and I don't even really mean to point fingers, that's actually just what it is. Making up a fairytale about history you can then wield as prior restraint.
For a more benign example, you've got Holly's Wiccans creating an entire new history from various pieces of myth and lore; for a more realistic example you've got the LDS Church building on a whole mythology about the American continent. In most cases, it's got a pretty large gender quotient, which is so far absent from this story, but the overall message -- that if Might has somehow stopped making Right, we have to reset the whole system so we're back on top -- is pretty standard.
In this case, the "Original Testament," which they call the Vampire Bible but seems more like the Vampire Book Of Mormon, tells a story where Lilith predates Adam and Eve both, because God is a vampire in this story, and she's created in his image. This means that Adam and Eve are a paired mating couple, meant to reproduce sexually rather than vampirically, in order to provide food for Lilith and her Brood.
Makes sense, I guess, these things usually do, but I think you should always question most those traditions and scriptures which support your right to primacy: Any belief you have which coincidentally puts you on top and somebody else on the bottom, and it should just be a natural moral reflex to question that and flip it over, because your own sense of self-preservation, your entitlement to whatever privilege we're talking about, is not going to do that for you.