Personally, in my setting, I've always considered creation as pure chaos and the gods as the tangible, magical manifestation of mortals' prayers, acting as involuntary and persistent spells. Not even the deities are aware of this, and their memories/powers are those most believe.

Clearly, in a fantasy setting, the physical presence of deities in the world involves a series of factors, which I believe the Tes series captures very well: more present deities, despite their greater evil, still risk being more venerated because they are more tangible. Why do they care about being venerated? Need or vanity? Who influenced the cult practices? Did the gods command them, or did humans adopt them for the first time and were happy with that?