There are those who came before, and there are those who came after. There are those who built the world, those who guard it, those who ascended from it, and those who tried to destroy it.
The ones who came before
The Old Gods, the ones who came before are the deities who created the Celestial Sea, and the ones who still maintain their light touch through the magic that permeates all. They are the most powerful of them all, and each one occupies a realm to him or herself. They are the ones who are revered before all others.
It is from their power that lesser deities form, and it is from their will that common mortals arose.
They rarely, if ever, interact with the mortal worlds, and only in the most subtle of ways, whether by answering a prayer with a cryptic riddle, or subtly altering small events, that would not reveal Heaven's design -- this is the principle of the old gods, and those who disobey must suffer the fury of his peers.
The ones who came after
The ones who came after are less powerful, less exhalted, and are usually the followers of a greater deity. That, or they were once part of the Greater Pantheon, but banished by the council. They take a more direct role in shaping the futures of their mortal subjects, and may even walk amongst the plains with them.
Some are born half-mortal, half-god; some received a greater power's grace; and some, via sheer determination and self-cultivation, found the gate to apotheosis and ascended to divinity.
They are usually worshipped by smaller followings, or as a messenger or prophet for a greater god. Some even, in rare circumstances, ascend to the position of lesser god through ancient arcane means known only to those who came before.