Multiverse Interactions

There are many material planes. The "Prime Material" is what residents of these planes usually call their own, because they're self centered jerks.
Gods can touch one or more of the planes. Like an empire that expands to different continents, they can be more or less powerful in individual places (based on the strength of their worship on that particular plane, among other things) but the power on one plane has some effect on the power of them all.
If a god is loses worshipers on one plane, the part of them that touches that plane can wither and ultimately "die", not being able to touch that plane. Just like destroying a colony doesn't destroy an empire, this won't kill the god on every plane simultaneously; but it will weaken them everywhere.