SmutDxddy
Well, it seems that Hermione already knows a little about Lucifer's religion, for his phrase: (I swear to God) and for reacting to Lucifer when he mentioned that he was an angel, Because if I didn't know anything, just like in the series, instead of swearing by God, I would swear by Merlin, so I would already know a little about God and religion in general, but not yet about Lucifer.