"All major religions achieved their growth and status by becoming the ideological arm of state power." I wonder whether that's true. Because it seems hard to distinguish from this: "All major religions, because of their growth and status, acquired state power which fuelled their further growth."

To distinguish between the two, we'd want to look for religions that (presumably by good luck) got significant state power before they became widespread. Someone who knows more history than me may have more clue here, but the only example I can think of is that of the pharaoh Ankh-en-aten (= Akhnaten), who basically tried to introduce monotheism into ancient Egypt, with scarcely any success after the end of his reign. That's hardly conclusive, but it seems like evidence for the hypothesis that widespread belief matters more than state power in getting a religion off the ground.