First, some gross oversimplification.
We have the timeless experience of gnosis; we have communities of Hellenized Egyptian Jews in the Ptolomaic period (350-30 BCE) writing about gnosis and using mythography to illustrate and amplify this experience (Let's call them "Gnostics" because honestly what else are we going to call them? Gnosis-ists?); we later have "The Jesus Movement" ("Early Christians")– Jews talking to other Jews about reforming Judaism; later still we have those gnosis-writing Hellenized Egyptian Jews incorporating Christian themes and characters into their literature (we'll call them "Gnostic Christians"); later later we see the Christian conversation spreading West and adopting much of the form and organization of Roman Paganism ("Orthodox Christians") – but this was merely one form of expression among many.
One of the people who was rather fond of that particular expression was Irenaeus, who argued for the primacy of his particular version. He was rather scathing of the competing forms, regardless of when they had shown up. He probably wouldn't have thought much of the Jesus Movement, had he been around 170 years earlier. And he certainly didn't think much of the Gnostics.
Irenaeus managed to do two curious things:
i) He outlined a plethora of opinions, practices, and quotations and attributed them, rightly or wrongly, to the Gnostics
ii) He ended up defining orthodox Christianity as the opposition to these same opinions, practices, and quotations. The end result is a wholly new religion that took his reading of "It's Not Judaism™" Paul and cranked it up to 11.
Right. So we have four distinct entities as a result of this:
a) the ongoing cacophony of the Christian conversation
b) A shiny new product on the shelf, Anti-Gnostic Iranaeus-Brand Christianity™, which would later be known as "orthodoxy"
c) the ongoing cacophony of what we now call Gnosticism, and
d) Iranaeus' (and later heresiologists') version of what he understood Gnosticism to be, or at least how he wanted it to be understood by others. Obviously, this is going to be a rather different from how any Gnostic at the time (regardless of what they called themselves) would actually present their world view.
Got it? Christianity-as-a-messy-whole, a spanking new Orthodoxy, Gnosticism-as-a-messy-whole, and Iranaeus' skewed interpretation of Gnosticism.
On and on through the hoary centuries, and the Gnostic conversation and the Christian conversation began to overlap less and less as the orthodox voice started to drown out everyone at the table. But that's history - a marketplace of ideas and movements, some adapt and become dominant, others retract and become recessive. The Gnostics never really went away, they endured in small, insular communities (such as the Mandaeans) or as a magnetic influence in others (such as the Druze or the Bogomils).
Okay, We're All Caught Up Now
Like I said, this is gross oversimplification. There's no way to accurately sum this up in less than a few thousand pages. But for our purposes, looking back over our shoulder, we see two distinct entities – what Gnosticism was, and what the heresiologists said it was.
Even then, "what Gnosticism was" was a whole series of competing, conflicting, nuanced, complex, occasionally bizarre takes on Greek myth and philosophy, esoteric Judaism, early Christianity, Egyptian cosmology, Hermeticism, and anything else that was lying around. There was no centralized, authoritative, definitive "Gnosticism" per se – just a literary and philosophical movement identified by its allegorical treatment of specific themes.
Anyway, if you throw all of that in a bucket and call it "Gnosticism", what we do know now is that when the heresiologists were talking about it, they got it all wrong. Either deliberately as a straw-man propaganda thing, or sheer cluelessness. But the stuff that was in the bucket, and what they said were in the bucket? Different things. Let's call them "Gnosticism" and "Heresiological Pseudo-Gnosticism". Kind of the same way we had authentic Judaism and what anti-Semites later described Judaism to be, blood of unbaptized babes and all. Different.
But it gets weirder.
Because so much of the contents of the original "bucket" were inaccessible to the West for so long, the only "Gnosticism" in town was Heresiological Pseudo-Gnosticism; deliberately misrepresented Gnosticism. And as orthodoxy centralized political power, it also accumulated all the blame that goes with such power, which is to say it started to annoy some populations rather a great deal. The thinking went that anything which bothered the powers-that-be can't be all bad, so we see some groups actually *endorsing* Heresiological Pseudo-Gnosticism as not only authentic, but a good thing, if only to annoy the orthodox.
"World-hating dualism" (and the mutually exclusive extremes of radical ascetism and wild libertinism), which certainly weren't present in the original bucket, featured prominently in Iranaeus' fever-dreams, and became the hallmarks of this word "Gnosticism". The heresiological hermeneutic got to own the word. For the most part, it still does (which is why it thinks it has the right to kill it). So some people embraced these ideas, and called themselves Gnostics. Some still do.
But now the cat's out of the bag – or perhaps more accurately the djinn is out of the jar – and we have access to primary source texts and know more accurately what the contents of the bucket actually were, why do we still have groups clinging to (and showing preference for) the heresiological view? Gnostics didn't actually draw straws to pick bishops the way Iranaeus said they did (and he didn't even actually say that, technically, which is a whole other layer of confusion right there) but some people identify as Gnostics because that idea appeals to them so much. Gnostics didn't hate the world, but some people hate the world and call themselves Gnostic as a result.
How amazing, elastic, capacious, are the original Gnostic myths that they can accommodate not only their original intent, but also their deliberate mischaracterization and still be spiritually valuable? It's astonishing. Miraculous, even.
There's a set-theoretic geometry trick called the Banach-Tarski paradox. You can jigsaw up a three dimensional sphere into bits, and reassemble those bits into two perfect spheres of the same size as the original. Shouldn't be possible, but it is, and thus a paradox.
Gnostic literature is subject to the Banach-Tarski paradox. You can take this rich, weird, lush vein of myth and symbol and rite and rant and argument, and you can spin it into the lovely po-mo Jungian Sophia-as-alchemical-insight; and you can spin it into the distinctly Christian you-hate-the-world-and-the-world-hates-you cranky dualist Sophia-as-whore bitterness of the heresiologists and their subscribers. Two perfect spheres extracted from the same source material, both in their way valid, provable, defensible – the same way you can extract a chunk of Paul and end up with Thomas Merton or the Westboro Baptists.
I've said before that we're the Gnostics now, and we get to decide what to do with this stuff. Anyone, anywhere, can pick up this stuff in translation (or slog through the interlinears, glossary in hand), identify with it, and own their response to it. We get to decide what this stuff means. And it's okay that we're going to see different communities coalesce around these different responses.
The conversation about how Middle-Platonic was classical Gnostic community x or how Christian was classical Gnostic community y is all well and good and fascinating (and keeps Brill in business), but as far as those first Ptolomaic Hellenized Egyptian Jews were concerned, those angelheaded hipsters burning for the ancient heavenly connection to the starry dynamo in the machinery of night, it was never about Gnosticism or Christianity or Judaism or any label to begin with.
It's about gnosis.
