Summary: The parable of the persistent widow in Luke 18:1-8 teaches us about persevering in prayer.
I read a story when I was a student at Trinity Evangelical Divinity School in Chicago, IL. You will be appalled by the story I am about to relate to you. Appalled, that is, if you have any kind of social conscience.
A poor black, living on Chicago’s South Side, sought to have her apartment properly heated during the frigid winter months. Despite city law on the matter, her unscrupulous landlord refused. The woman was a widow, desperately poor, and ignorant of the legal system; but she took her case to court on her own behalf. Justice, she declared, ought to be done. It was her ill fortune, however, to appear repeatedly before the same judge who, as it turned out, was an atheist and a bigot. The only principle by which he lived was, as he put it, that “blacks should be kept in their place.” The possibilities of a ruling favorable to the widow were, therefore, bleak. They became even bleaker as she realized she lacked the indispensable ingredient necessary for favorable rulings in cases like these – namely, a satisfactory bribe. Nevertheless, she persisted.
At first, the judge did not so much as even look up from reading the novel on his lap before dismissing her. But then he began to notice her. Just another black, he thought, stupid enough to think she could get justice. Then her persistence made him self-conscious. This turned to guilt and anger. Finally, raging and embarrassed, he granted her petition and enforced the law. Here was a massive victory over “the system” – at least as it functioned in his corrupted courtroom.
In telling you this story I have not, of course, been quite honest. For this never really happened in Chicago (at least, as far as I know!), nor is it even my “story.” It is a story I have borrowed from David F. Wells , who in turn borrowed it from Jesus in a parable he told in Luke 18:1-8 (quickview)  to illustrate persevering in prayer.
1 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 faith on earth?” (Luke 18:1-8 (quickview) )
Jesus was on his way to Jerusalem. He was most likely in the final few weeks of his life before his crucifixion. While traveling to Jerusalem Jesus taught many important truths that he wanted his disciples to understand and apply to their lives.