Here's another: gods are powerful spirits, or "principles", if that makes any sense, that have effect in the world, but don't care that much about particular events or even those hardly discernible mortals.
It is the faith, that attracts them to the world and its affairs, like a magnet attracts metals. Perhaps this is unrealized or even unwanted by them, or they don't really care what they attend to in the end. If there is an unlimited number of things to do, you can do this or that, or just pick whatever grabs your attention - and those mortals are sooo demanding at all times.
If the faith starts to dry up, this particular breed of gods would simply return to whatever other job they used to have, losing interest in their worshippers. If more people were to worship them, they would be dragged back.
(Ironically, in this particular setup, if sufficiently important spirits were to forced into the role of gods, they could neglect their duties and create some serious difficulties in the world. Solve that one!)