The best-written expansion of Kirby's Fourth World that I'm aware of is the 1988 FOREVER PEOPLE 6-issue limited series, By DeMatteis and
Paris Cullens. Particularly issue 5.

It captured well the spiritual warfare of good and evil gods, using earth and its people as the battleground. It's the aspect I like
best, the New Genesis gods constantly inspiring humans to personal achievement and acts of love. While Apokalips gods draw humans into
bitterness, division, war and genocide.

I actually was disappointed with the different direction the Dematteis/Cullins FOREVER PEOPLE miniseries went at the end, in issue 6's conclusion.
But it was still interesting and well-written.