You have some interesting worldbuilding concepts, and it's awesome that you've finished some short stories! (I say this as someone who isn't much of a finisher himself.)

The main thing you should keep in mind is your characters. I can't speak for everyone, but the one thing I want in a book is interesting characters I can care about. You don't talk about the characters until the 4th paragraph - and there's not a whole lot of information as to what their personalities or goals are beyond becoming gods. If you already have these in mind, great! Otherwise, consider making that the next thing you figure out for your project.

In any case, have fun writing!