Luke 18:1-8 contains the Parable of the Persistent Widow. Luke prefaces Jesus' narration of the story of the widow's pestering of the unjust judge with the comment that our Lord gave this parable specifically to encourage people "to pray and not lose heart." The basic subject of this passage of Scripture deals with the question: Will a person ultimately cave in, downcast and discouraged, because of the difficulties and trials he faces throughout his Christian life, forsaking all the truth and opportunities God has given him?
Christ's parable teaches us that we are to continue to pray and not falter or become dejected if our prayers do not seem to be answered right away. We are to come to understand that if a request is not granted immediately, God may be testing us, teaching us patience, or working out a purpose we cannot see. We must understand that He works on His timetable—not ours—and that He always works out what is best for us and for our particular situation (Romans 8:28). Our job, then, is to persevere in our faith in God, always trusting Him in what we ask of Him.
In the parable, we see the widow coming before the unrighteous judge with her complaint, though Christ never informs us about its specifics. We do not need to know the details; it could be any grievance. The callous judge has no pity in him, but the widow is so persistent that the judge reasons within himself that he had better avenge her lest she wear him out with her incessant visits. The phrase "weary me" literally implies striking blows and giving the recipient a pair of black eyes! This was one persistent woman!
If a reader of this parable is not careful, he could judge God as being comparable to the unjust judge, that is, that He will not answer our requests promptly unless we bother Him with constant pleas for help. Actually, Jesus is contrasting the faithfulness of our loving God to the cynical, self-serving, unrighteous judge. The latter is not in any way a good man, but a godless one who is just trying to shield himself from being annoyed.
Jesus is trying to get us to realize God's never-ending love and faithfulness to His children. We are to see that all that God is, the judge is not. God is always willing to hear us and to answer our prayers if according to His will. He always hears the cries of His own elect or chosen ones. Indeed, God will avenge or vindicate His people.
The point is that, if the unjust judge—who could not have cared less for the widow—at length responded to her cry merely to rid himself of her aggravating requests, then shall not God—who loves His chosen people and gave His Son for us—answer our prayers when we are under trial or in need?