I know a church where they stopped using incense after they had fitted smoke alarms. Fire is dangerous but sometime you have to take a risk. Imagine what would have happened to our faith if Moses had used a fire extinguisher rather than venturing into the presence of God at the burning bush.
But you may feel uneasy when you hear Jesus wanting to bring fire to the earth. There are too many terrorists around at present who are willing, for a greater cause, to burn up themselves or bring down fire on their enemies and the innocent. Is it destructive fire like this which Jesus wants to use?
Elijah had certainly called down fire on his enemies, but when the disciples earlier in the Gospel asked Jesus whether he wanted them to imitate the prophet and destroy the Samaritans with fire, he rebuked them. But Jesus could still be using the fire of judgement which would not destroy but reveal God's truth, disturb the peace and bring down hatred upon his head. And in this he would be more like the prophet Jeremiah.
Jeremiah knew that Judah was riddled with injustice but that no one wanted to admit this. The false prophets advocated peace at any cost and papered over the corruption. Jeremiah also knew what the cost would be if he opened his mouth and spoke the truth. But he could do no other. He tells us in chapter twenty that
there is something like a burning fire shut up in my bones. I am weary with holding it in and I cannot.
He must speak God's word which prophesies that it will only be through the crucible of exile that healing will come to the nation. Judgement is the only way to true and lasting peace. But how do his listeners react? They douse these prophetic flames by throwing him into the mud at the bottom of a well. But this is what happens to prophets who risk playing with fire.
Jesus, like Jeremiah, knows that lasting peace will only come when his words are heard and people change their behaviour. When he goes to the Temple he condemns this central institution of the nation as corrupt. And inevitably his words cause divisions.
But instead of throwing an incendiary device at his enemies, Jesus prefers to take on himself the effects of the peoples' sin. John the Baptist had earlier prophesied that Jesus would bring a baptism in the fire of the Holy Spirit. At Pentecost the disciples will indeed receive the Spirit in for form of tongues of fire. But before this can take place Jesus must face his own baptism of fire through the sufferings he will endure in his passion and death.
But today in the Gospel he expresses a passionate impatience; he yearns for this baptism just as he yearns to share the passover meal with his disciples. It will only be through his act of sacrificial love on the Cross that his disciples will be able to receive that baptism of the Holy Spirit at Pentecost. Having plumbed the depth of human injustice and passed through death the risen Jesus can give them the gift of an enduring peace through the power of the Holy Spirit. But that peace will bring with it, as Jesus predicts and as the Acts of the Apostles reveal, divisions in families and households.
That gift of peace is still on offer. But just as many turned away from Christ's words in his own day people still prefer a quiet domestic peace which allow the deeper injustices and problems in their lives to be ignored. The Church too often puts out the fire which Christ wishes to bring to the earth through timidity and fear. It can often give the impression it wants peace and quiet and does not want people to be disturbed in their faith, although Jesus did not have the same anxieties.
But just in case you are ready to cast fire you should at least take the fire test. Before you cast the fire in righteous anger against others make sure you are willing yourself to take some of the same heat which Jesus felt in his baptism of fire.