the song was meant to be "what if slaves didn't find Jesus, but Satan instead"

If accounts of the conquest of Benin are anything to go by, satan was already well known in West Africa back when the natives were selling off prisoners as slaves. The tl;dr is that after ambushing and killing a bunch of Brits, they tried to stop the resulting punitive expedition by torturing a ton of slaves to death in blood magic rituals. The details are fucking horrifying and shouldn't be looked up unless you have a strong stomach.