The religions refer to these deities that had this influence over humankind. Why are they in hiding now? I know this is a rhetorical inane question. Just saying if they need to worship, one would think they would like to see what it is they are worshiping? Most of the rituals they follow are Pagan in origin and if I remember correctly pagan were the people that followed the god Pan and Pan was the word adopted by Hades.
back in the dusty shelf, where they belong.
I figger they proly got to fighting among theyselves and kilt each other off.