>jedi have super powers therefore their religion must be true
Everyone arguing that Han’s skepticism is a plot hole is retarded. Everyone (except for Luke the country bumpkin) knows what that Jedi existed, what their ideology was, what powers they had (Jabba calls out the Jedi mind trick by name). Even if their numbers were never great Jedi had enough notoriety to be know in all republic space (Anakin knows who Jedi are in Episode I).

Han, the Imperial Officer, etc. deny the Jedi’s ideology: that there is a supernatural transcendent Force that connects all life in the universe and will bring about good if you trust It. And considering everyone that adhered to that faith got slaughtered, it’s a pretty reasonable conclusion to make.