Blake had an interesting conception of heaven and hell. From The Marriage Of Heaven And Hell:

Without Contraries is no progression. Attraction and Repulsion,
Reason and Energy, Love and Hate, are necessary to Human existence.
From these contraries spring what the religious call Good & Evil.
Good is the passive that obeys Reason. Evil is the active springing
from Energy. Good is Heaven. Evil is Hell.

Whilst on Blake, how about this for refutation that there is such a dismal concept as "the mundane":

"To see a world in a grain of sand
And heaven in a wild flower,
Hold infinity in the palm of your hand,
And eternity in an hour"

I like this a lot, though in other ways Blake could get a bit mystical for my taste. I wonder whether he thought he was, or whether that's just the way we've come to see him. I thing the most extraordinary thing about the world around us is the sheer, wonderful ordinariness of it all, the utter normality. There's plenty enough to revel in. I don't want some extra mysterious sheen on it all that I can never quite reach. I just don't think that's the way things are. The mysteries of the downright ordinary stuff will do me. I think "the mundane" can only be the invention of tired minds.