Initially, Old Testament prophets like Moses and Elijah were commanded to speak plainly to Israel in the form of sermons. But Israel refused to listen; therefore later prophets used a different method. They began using parables and symbolic actions (e.g. Ezekiel 24:3). There was to be a twofold effect of parables: the hardened will be further hardened and ultimately judged (e.g., Isaiah 6:9–10, followed by Isaiah 7:3–9; Isaiah 8:1–4), the righteous will respond appropriately with obedience (e.g., 2 Samuel 12:1–31).1
In telling parables, Jesus therefore continues with the way they were used in the Old Testament. He uses them to divide between those who are righteous (insiders) and those who are hardened (outsiders). Passive listening to Jesus makes a parable meaningless but active listening unlocks the meaning.
11 And he said to them, “To you has been given the secret of the kingdom of God, but for those outside everything is in parables,