The Persistent Widow
Jesus occasionally compares human beings to God. For example, in his most famous sermon, he asks “ which of you …?” to compare our parenting instincts to God’s. Similarly, in two of his parables, he also asks “ which of you …?” to compare our care for what is valuable to us with God’s care for what is valuable to him (us!)

In this parable, however, Jesus compares a decidedly unpleasant character to God! The “unjust judge” in this story “neither feared God nor respected man.” And yet because it was her only avenue to justice, a mistreated widow approaches this judge incessantly. Because of her persistence, Jesus tells us, her suit is eventually processed by the judge.

Sometimes it seems like our prayers are not answered. Sometimes it seems like God, if he is listening, cares for us about as much as the judge in the story cared for the widow. Jesus isn’t unaware of this reality. But he wants us to understand that God does care, and God does listen, and that we should not lose heart when we come to God for justice. Persistence in prayer is part of what it means to be watchful and ready . As Jesus teaches elsewhere:
Luke 18:1 (ESV) And he told them a parable to the effect that they ought always to pray and not lose heart. 2 He said, “In a certain city there was a judge who neither feared God nor respected man. 3 And there was a widow in that city who kept coming to him and saying, ‘Give me justice against my adversary.’ 4 For a while he refused, but afterward he said to himself, ‘Though I neither fear God nor respect man, 5 yet because this widow keeps bothering me, I will give her justice, so that she will not beat me down by her continual coming.’” 6 And the Lord said, “Hear what the unrighteous judge says. 7 And will not God give justice to his elect, who cry to him day and night? Will he delay long over them? 8 I tell you, he will give justice to them speedily. Nevertheless, when the Son of Man comes, will he find faithfulness on earth?”
"Watch and pray that you may not enter into temptation. The spirit indeed is willing, but the flesh is weak. (Matthew 26:41, Mark 14:38)." Paul concurs: "Continue steadfastly in prayer, being watchful in it with thanksgiving (Colossians 4:2)"

Finally, Jesus indicates that as time progresses, it might become increasingly difficult for humanity to demonstrate the kind of faith that he requires. I'd like to be found ready...