When Jesus spoke of his coming to start (literally, “cast”) fire on the earth, he may have meant the fire of a refiner. (Luke 12:49) A Messianic prophecy (Malachi 3:2, 3) pointed to his role as a refiner’s fire. His works, his matchless example in the display of love, compassion, and justice, and his teaching functioned like a refiner’s fire. This fire tested the deep inner selves of the people and revealed their attitude and motives. By his words and actions, Jesus exposed who among the people were like the worthless dross of the refining process or the precious metal that could be purified and rendered suitable for the realm where his Father is Sovereign and he is the appointed king.
The fire that Jesus started through his miracles, teaching and example proved to be only the initial phase. His desire was that this fire would burst into full flame. (Luke 12:49) This would happen after his death, resurrection, and ascension to heaven, as his disciples would proclaim the news about him and the message would reach far beyond the borders of Judea, Galilee, Samaria, and nearby regions.
The Son of God knew the suffering that lay ahead for him, which included an agonizing death. He referred to the agony that would culminate in his sacrificial death as a baptism with which he had to be baptized or immersed and added, “And how distressed I am until it is finished!” (Luke 12:50) That baptism had to be completed before the “fire” became an unstoppable blaze, spreading quickly to the distant parts of the Roman Empire.
The result would be serious rifts even among close family members, with some putting faith in Christ and others persisting in unbelief and becoming hostile. Therefore, Jesus indicated that those listening to him should not think that he had come to bring peace to the earth, but rather to cause division. His coming forced individuals to take a stand for or against him. Among five family members, three unbelievers might choose to oppose two believers, or two unbelievers might take their stand against three believers. Families would be divided, with a father against his son, or a son against his father, a mother against her daughter, or a daughter against her mother, a mother-in-law against her daughter-in-law, or a daughter-in-law against her mother-in-law. (Luke 12:51-53) Earlier, when sending out the twelve apostles, Jesus had also spoken about the divisions that would come about (Matthew 10:34-36), and the language he used parallels the words of Micah 7:6.