Many believe Jesus told parables to his followers because he was revealing some kind of new resurrection and kingdom. However, Jesus made clear that his parables were told to unbelievers, to confront them in their ungodliness: “The knowledge of the mysteries of the kingdom of God has been given to you, but to others I speak in parables, so that, “though seeing, they may not see; though hearing, they may not understand.” (Lk. 8:10) The Gospels elsewhere confirm this approach (cf. Mk. 4:11; Mt. 13:13). Jesus never sought to change the commonly understood Jewish eschatological hope.
When Jesus spoke of the “mysteries” of the kingdom, he was referring to the dichotomy between this age and the age to come, where “many who are first will be last, and the last first.” (Mt. 19:30) In Jesus’ day (as it is today), many believed themselves to be superior to others, and thus they thought they would be “first” in the resurrection, receiving the greatest reward in the age to come. But Jesus used parables to confront their pride and arrogance. Though they believed they would be first, they would actually be last (i.e., along with the pagans, they would actually be thrown into Gehenna!).
Most of Jesus’ parables thus make a simple delineation between the righteous and the wicked. This was done to cut through the confusion caused by the pretense of those who saw themselves as great. The merciful and repentant would be counted righteous, while the arrogant and prideful would be counted wicked. Imagine the offense of Jesus hanging out with “the sinners,” while condemning “the righteous” to hell. This is the mystery of the kingdom: the order of the Earth will be radically reversed on the Day of the Lord, and the meek will inherit the earth.