Fire, in the spiritual sense, can mean either love or hatred depending on the context, just as natural fire can be either comforting in keeping you warm, or scary in burning down your house. Our language reflects this, too -- we use concepts like a smoldering hatred or a burning love. So fire signifies a love, either a good love of the neighbor and to the Lord, or, in a bad sense, selfish love of oneself that, if unchecked by conscience, leads to hatred of anyone that opposes it.

126. LIGHT AND HEAT IN HEAVEN.

That there is light in the heavens those who think from nature alone cannot comprehend; and yet such is the light in the heavens that it exceeds by many degrees the noon-day light of the world. That light I have often seen, even during the evening and night. At first I wondered when I heard the angels say that the light of this world is little more than a shadow in comparison with the light of heaven; but having seen it I can testify that it is so. The brightness and splendor of the light of heaven are such as cannot be described. All things that I have seen in the heavens have been seen in that light, thus more clearly and distinctly than things in this world.