Imagine a world where ultimate vindication will come, but knowing that ultimate vindication will come does not lead to passivity but to the demand for justice in prayer.
So the Parable of the Unjust Judge in Luke 18:1-8. It teaches us not so much to badger God until he gives in, but that God is just, God will bring justice, and we are to go to God in pleading for justice even now as we wait.
One of the issues this parable imagines for us is this: Does the patience of God, or the lack of justice in our world now, lead people to ignore justice issues, suppress justice issues, or go to God for justice? No one who goes to God can at the same time not be working for justice.
The major distinction between life now and life in the kingdom is that the latter is a world of pure justice and the world now one mixed up between injustice and justice. That is the condition of the world. This parable urges us to imagine a new way: a world that is marked by injustice but a people that will not stand for it and who do something about it.
And God, Jesus wants us to imagine, is not like that Unjust Judge who must be badgered and bothered in order to respond. God is good, God is just, God wants his people on his side — the side of justice. Imagine that kind of world and we will all be different. Amen?