It depends on where you’re talking about. But in places like France the Catholic Church was seen as an oppressor because (they wanted to to be seen as the only place/ source for truth). The church also used their sway over people into making them be extra harsh on themselves about sinning because they wanted the people to think that that the only way for forgiveness of said sin was through religion. So naturally when enlightenment and science revolution came about the church had something to fear for. Since enlightened people focused on the idea of individuality through educating others and having reasonings.