People have not realized before that there is another sun besides the sun of our physical world. This is because our spiritual nature has become so deeply involved in our physical nature that people do not know what the word “spiritual” means. So they do not realize that there is a spiritual world other than and different from this physical one, a world where angels and spirits live.
Because that spiritual world has become so completely hidden from people in this physical world, the Lord has graciously opened the sight of my spirit so that I can see things in that world just the way I see things in this physical world, and then provide descriptions of that spiritual world. This I have done in the book Heaven and Hell, which has a chapter on the sun of the spiritual world. I have in fact seen it, and it seemed about the same size as the sun of this physical world. It had a similar fiery look, but was more reddish. I was given to understand that the whole angelic heaven lies beneath this sun and that angels of the third heaven see it constantly, angels of the second heaven often, and angels of the first or most remote heaven occasionally.
It will be made clear in what follows that all their warmth and all their light—everything people see in that world—comes from that sun.
That sun is not the Lord himself, though it is from the Lord. What looks like the sun in the spiritual world is the emanating divine love and wisdom. Since love and wisdom are one in the Lord, we say that this sun is divine love. Divine wisdom is actually an attribute of divine love, so it too is love.
from Divine Love and Wisdom, Sections 85, 86