Fire
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.
Matthew 16:1-4
1
The Pharisees and Sadducees came, and testing him, asked him to show them a sign from heaven.
2
But he answered them, "When it is evening, you say, 'It will be fair weather, for the sky is red.'
3
In the morning, 'It will be foul weather today, for the sky is red and threatening.' Hypocrites! You know how to discern the appearance of the sky, but you can't discern the signs of the times!
4
An evil and adulterous generation seeks after a sign, and there will be no sign given to it, except the sign of the prophet Jonah." He left them, and departed.
