So no one has yet covered what influence faith has on the deities. And if faith or human perception actually shaped these particular god-like foreces or ideas in some way.
Therefore, in this model, gods are mutable, and become what is believed.
They might have originally been simply the force of the sea, or just an energy of the underworld, but what people believed shaped them
Thus, there is a creative force which brought the world into being, and the gods were simply a part of that godlike energy, eventually breaking off into parts, as they got to be too large when fed by belief.
In the realm of the dead, you go to the place you believe in, with the god you believe in.
There's a couple of ways to do this:
- Gods have different aspects in different places, but they are actually the same energy--Zeus with a different name and aspect. They may even have a multiple personality thing going and will only dimly be aware of the other apsect. On a cosmological scale, they do the job (so if you're talking Sun god, they get the sun where it should be, in their purest form) and only take the culturally prescribed form/aspects/personality--maybe even picking up slightly different abilities for each.
- Gods were once part of the same energy, but keep breaking apart Start with a creator god. That god breaks off into different energies because She can't be everywhere at the same time. Then humans start worshiping these different energies, their faith and ideas defining them and feeding them. Different cultural beliefs cause them to split into different entities. With something such as a hearth god or agricultural, that's very much a local thing, and there's no need for the energies to join forces to create an effect (as there would be for a sun god). So, for instance, one sun god uses a chariot, so over those countries where that is the belief, it is so. Where it is the eye of the god, it is so--it's all about WHERE you are standing on earth. If you were on the sun and looking at it, it would only be energy, the function would be performed no matter what, but as the sun shines down on two different countries at the same time, both aspects are true, maybe even AT THE SAME TIME.
The more local the force is, the less likely there would have to be cooperation. A god of thunder in one area could be different from a god in another area, but sun gods would have to cooperate. In a mixed culture there would be clashes and even wars. The gods would use people to spread belief in their pantheon (or team) and it would be very important to them to keep cultures protected from the influence of other pantheons. Having an arbiter god which is a combined aspect or the highest of gods might be a good way to solve disputes and keep a balance.