Well, for years those advocates did so with censorship, gaslighting, destruction of property, threats and calls for violence, etc. They had a hysterical fervor and lack of rationality that did often seem quasi religious. I dont think Paul's understanding is perfect but the parallels to religious puritanism are quite obviously there.
> They had a hysterical fervor and lack of rationality
Of all the ways of attacking a class of people, labeling them as gaslighters while at the same time calling them crazy is certainly one of them.