Both readings in the Old Testament speak of the vineyard and of the Judgement upon it. As Isaiah put it, God looked for justice, but saw bloodshed; for righteousness, but heard cries of distress. NIV
Jesus seldom spoke of this aspect of his role of Messiah, but it was always present in the undercurrents. When John the Baptizer talked about Jesus, he said that Jesus will baptise you with the fire of the Holy Spirit. He will come all ready to separate the wheat from the chaff, and to clear the rubbish from his threshing-floor. The wheat he will gather into his barn and the chaff he will burn with a fire that cannot be put out. Phillips
So, when Jesus said, I have come to bring fire to the earth, Phillips he is not saying anything new. In fact, the idea that the Messiah would cleanse the land was commonly understood among Jews of Jesus day, based on many texts in the Old Testament.
We also need to connect that fire with the Spirit. Ruach is the Hebrew word meaning spirit but also meaning breath and wind. Pneuma is the Greek word which means spirit, breath, and wind.
A strong biblical image involves the thrashing of wheat. Before the machines of the Nineteenth Century, grain was cut and tied into small bundles called in America, shocks, or sheaves in Europe. These shocks were taken to an open area and beaten on a stone or hard floor until the grain popped loose from the head. This was done on windy days so that the lightweight chaff would blow to the side, leaving a pile of clean grain. It was as true in Jesus’ day as it is today that the purest grain earns the highest price.
To complete the ancient picture, once the grain had been scooped up and safely stored, the chaff that had been removed by the ruach/pneuma, it was burned. In the physical sense, wind and fire worked together to keep the grain pure. In the theological sense, the Holy Spirit separates the impure people from the pure and the impure are cast into the fire.
Jesus was expressing his eagerness for the process to begin purifying God’s Creation.
We now live in a world between the beginning of purification and the unseen end of it. The author of Hebrews describes what we are experiencing by listing what happened to God’s faithful even before the days of Jesus.
We should expect no less in our own lives. Living a life dedicated to doing good as God sees it will naturally invite others to criticize us, even some of the people of God. We live in a world where people suffer, good and bad. When we leave this world and stand before God, His Holy Spirit will blow away those who opposed God. They will receive their reward. Those who are the real grain of the Work of God will remain before Him.
Keep the faith.
Be righteous and do good.