Satan disproves Christianity by not being the devil in the Old Testament [the foundation from which Christianity is born and relies upon to be valid] but rather being an agent of Yahweh who is meant to test mortals on their faith in Yahweh.
He didn't become a rebellious demon thing until Christianity, when they realized they needed a new threat to get people to flock to their cult when it was becoming rapidly very obvious that the polytheistic Romans weren't being stricken down with horrible plagues and shit by the supposedly omnipotent Yahweh despite their endless blasphemies against Yahweh.
Look to the foundations when you wish to demolish something, for when they are weak or destroyed, the entire structure comes crumbling down.
He didn't become a rebellious demon thing until Christianity, when they realized they needed a new threat to get people to flock to their cult when it was becoming rapidly very obvious that the polytheistic Romans weren't being stricken down with horrible plagues and shit by the supposedly omnipotent Yahweh despite their endless blasphemies against Yahweh.
Look to the foundations when you wish to demolish something, for when they are weak or destroyed, the entire structure comes crumbling down.