Will not God give justice ...
And he told them a parable to the effect that they ought always to pray and not lose heart. He said, “In a certain city there was a judge who neither feared God nor respected man. And there was a widow in that city who kept coming to him and saying, ‘Give me justice against my adversary.’ For a while he refused, but afterward he said to himself, ‘Though I neither fear God nor respect man, yet because this widow keeps bothering me, I will give her justice, so that she will not beat me down by her continual coming.’” And the Lord said, “Hear what the unrighteous judge says. And will not God give justice to his elect, who cry to him day and night? Will he delay long over them? I tell you, he will give justice to them speedily. Nevertheless, when the Son of Man comes, will he find faith on earth?”
I have read this passage many many times and have never really noticed the word "justice" in it.Jesus not only uses the word in the parable but he then speaks of God giving justice to those "who cry to him day and night". Why do you think that he speaks of this connection between justice and persistent prayer? Possibly the only response to the injustice in this world is prayer that does not cease but causes one to rise up acting and interceding for the helpless?
The second connection to prayer in this passage is the one to faith and faithfulness. The Lord closes the parable by asking a question about faith. It is like he is saying: "Yes, I know that you believe while I am here but will you continue to believe ... will you continue to pray.. once I am gone". The hallmark of a believer is prayer. A person who does not include God into every part of their life through prayer misses the greatest of joys that this life affords.
For this day Lord, we pray for the justice that happens when your kingdom comes and your will is done.