The level of existence of each worshiped gods, is based on their tellers(I don't want to think of a better sounding word) such as prophets, priests, preachers, witnesses or even commoners, without them, a god will not be believed by multiple person, I think it's up to their tellers. Some Gods though met by people themselves like those on Hinduism, but it's easy to conceal that it was made up or half true(similar to some sengoku animes).
The way they say it is claim like the world is attached to Yggdrasil, and claim of nature like Helios pulls the sun. Not real since they don't happen completely.
I know it's damn boring having no afterlife but jews can have been happy without it.
My plan when I die, is at least my Gentlepervert part 2 becomes the greatest warrior known to man.