Jesus speaks through difficult metaphors sometimes. The metaphor of fire is the difficult one we encounter today. Fire has been used as a sign of destruction in the story of Lot. The book of Revelation has at least half a dozen connotations for fire. The most significant biblical meaning of fire is as a purifying agent, like gold is purified in fire. Prophet Isaiah refers to an angel bringing fire from the heavens and touching his tongue with it to cleanse away his sins. Then, he becomes ready to be sent on God’s mission. That was the cleansing fire. Fire is also the symbol of the Holy Spirit. Remember the Pentecost experience. In recent literature fire symbolizes passion or deep desire.
Identifying what Jesus intended by fire is crucial in finding the meaning of this text. There are some Christian sects that make very literal interpretation of this passage and depict the last judgment scene with a lot of cauldrons of fire where the sinful are pushed and consigned to. The literal interpretation simply fails to explain the loving and caring Father who Jesus came to teach us about. This interpretation fails to show, if Jesus came to put fire, why he lived without burning even a dry leaf. Remember there was a reminder from the disciples to call fire on the people. Jesus rebuked them for suggesting such a stupidity. So a literal interpretation is an immature understanding of the Scripture.
What does fire stand for, then? Fire as a purifying agent is how we can best understand this metaphor. The toughest impurities in gold are removed by melting it in fire. So are our own impurities deeply stuck in our life need to be purified. The fire that helps us discern right from wrong is the Holy Spirit. Remember the image of the tongues of fire associated with the Holy Spirit at the time of Pentecost.
Changing self-seeking behaviors is the greatest trial we have to undergo. As soon as we receive the Spirit, this trial begins. Remember when Jesus was baptized and filled with the Spirit, he went to the desert where he was tested. Tested against every sort of self-seeking desires. He came out not succumbing to such temptations. The Holy Spirit is the fire that tests us and purifies us. Remember Matthew and Luke associate baptism with fire (Matthew 3:11; Luke 3:16). The fire that does not consume the goodness in us is the Holy Spirit.
I am sure, you are by now reminded of the burning bush experience of Moses. The fire that he saw in the bush without consuming it had begun to burn in himself as well with that experience. He begins to work for the good of others. Moses who had run away from the Egyptians for fear became courageous after the burning bush experience. This fire cleanses us from self-seeking desires. Once such self-gratification needs are put out, the new fire for working for God begins. Moses found the courage to work for the Israelites from that experience.
The disciples, after the experience of the tongues of fire, also suddenly get the courage to speak to the people who singled them out to be arrested. The fire stands as the symbol of the Spirit that purifies our self-seeking desires which are at the root of most of our fears and anxieties.
When the symbol of fire came together with the discussion on peace, understanding the text has become more difficult, especially when Jesus, the Prince of Peace, announces that he did not come to sow not peace but discord. Well, the early Christian community was facing the problem of having some members of the family part of the Church and the others sticking to the Jewish or other traditions. This had naturally disturbed the peace in families. It is in this context that these words are narrated to the community as a catechetical example.
It is good to reflect over what greenery is in me on which the Holy Spirit burns. The Spirit works on our nature and there is no one who is without some greenery of goodness. The Spirit fosters that goodness. Identifying the goodness is as good as identifying what drains my energy for unproductive growth. These unproductive branches must be burned away. The Spirit will help us do that. But we need to be willing to let go of the affinities to things, ideas and tendencies that do not build humanity and leave us hollow and empty. That willingness happens by choice. The Holy Spirit can cast the burning shadow on us only if we are malleable.