Earlier quoted context omitted.
My reading is that the very fact that it's so abstract and general is itself the point. What could the cult be? Politics? Religion? A particular professional mindset or focus? Many could fit. Apart from the reference to "promise of godly exaltation or gift in a theoretical afterlife" (which nod towards religion), you could apply a lot of this to many social groups.
Yup, the rest could apply to just about anything, but this brief phrase near the end makes it pretty clear that it's about religion. That, and phrases like "the cult has left noticeable marks on you". Somehow all atheists (or at least the militant kind) seem to believe religious people are all deeply scarred and twisted, no matter how "watered-down from its original form" their "cult" may be.
It's brilliantly subversive and makes you think.