Luke places the parable of the unjust judge (Lk 18: 1-8) here at this point to further stress the message of the preceding instruction. He relates the two episodes by referring to the ‘coming of the Son of Man’ in Lk 18: 8. The two parables that follow express and contribute to the over-all message of the eschatological instruction in Lk 18: 22-37. Besides, as we have noted earlier, Luke has a deep interest in prayer, which is one of the themes developed here.
The purpose of the parable is stated in the introductory verse: to stress the need to pray always and persistently without ever giving up. Luke wants the persecuted Christian community of his time to realize that God will not abandon them. By persistent prayer they ought to remain faithful and vigilant until the return of (the Lord) Jesus.
The traditional title of the parable, “the parable of the unjust” judge is one-dimensional. In fact, we have two characters: the persistent widow and the judge who, because of persistence, vindicates the persecuted widow (Cf. Lk 7: 11-17; 20: 45 – 21: 4). The soliloquy of the judge (Lk 18: 6) is meant to draw the listener’s attention to the point of the parable. The parable emphasizes that the judge yielded to the widow’s plea, neither because of any religious value nor because of public opinion (Lk 18: 5). The message of the parable is powerful: If persistent plea is effective with an unjust judge, then how much more effective would it be with God, the just judge? In this perspective, the message of the parable hardly differs from that of the parable of the persistent friend in Lk 11: 5-8. The need for persistence and continual prayer is thus stressed.
In verses 7-8a, we have an application of the parable and extension of its meaning. It is done through allegory of a point in the parable, namely vindication. The two rhetorical questions are to be noted: “will not God vindicate his elect?”; “will he delay long?” Yes, the Christian disciples can certainly rely on God who will listen to their request and intervene in their distress. Besides, unlike the unjust judge, God will act speedily to vindicate his elect, the (persecuted) Christian disciples.
In verse 8b, there is a further extension of the meaning of the parable. Christian prayer should not only be persistent and continual; it must also be faith-filled. It is faith that should motivate such prayer. The rhetorical question, “when the Son of Man comes, will he find faith on earth?” thus relates this instruction o prayer to faith. Moreover, the title “the Son of Man” connects this parable to the preceding instruction on the day of the Son of Man (Lk 17: 22-37). The parable would then mean that the disciples are to pray continually and with faith. Otherwise, it may happen that when the day of the Son of Man finally arrives there would be no faith at all. There is a danger that when God finally interlines, the believers may not be prepared for it. The final question in verse 8b emphasizes this danger. The faith meant here is the commitment to the Lord, manifested through faithfulness to his message. Therefore, it is all the more necessary to remain faithful to the end, in prayer.
The meaning of the question is to be also seen in the context of the delay of the Parousia and the experience of persecution of the opposition to the Church. The Church therefore, has to feel the need to pray continually without ever losing heart. It ought to pray with faith which inspires and sustains persistent prayer to God, who alone will vindicate it.