The chapter break is misleading, since this parable very much follows on from the previous section, beginning at 17:20, which is all about Christ’s return and the coming of the Kingdom. The final verse of the parable (18:8) makes it clear that Jesus is still talking on that subject. So the kind of prayer that Jesus has in view here is particularly prayer for Christ’s return, prayer that God would come and right the wrongs in our world and vindicate his people. That’s the day we should long for (cf. 17:22), and what we long for we should pray for (“your Kingdom come”).
The point of the parable is not that God is rather like that unjust judge, so if we pester Him long enough we’ll eventually get what we want; the point is made by way of contrast – God is not like the judge. If even a godless, corrupt judge will give justice, how much more will God bring about justice for His people! The widow was someone of no consequence to the judge, but we are God’s “chosen ones” (v.7). It’s not a call to persistent prayer on the basis that if we nag God long enough, and prove we really want something, we will overcome His reluctance (that’s to babble like pagans), but a call to pray because we know God is good and loving and just. The phrase at the end of v.7 – “Will He keep putting them off?” – speaks more literally of His patience in delaying His judgment (cf. 2Pet.3:9); His slowness in answering is not the reluctance of an unjust judge, but the patience of the merciful saviour.
Verse gives the conclusion, which makes two points. (i) God will bring about justice and “quickly”, in the sense of suddenly. He is patient, but when He finally acts He won’t hang about, retribution will be swift and sudden. We can be absolutely certain of God’s justice. What is less certain is (ii) whether we will show faith like the widow, that holds on to God’s promises. Faith, in sharp contrast to the people of Noah’s and Lot’s day (17:27-29) who were preoccupied with this life, that longs for and lives for and prays for that coming Day.
Few parables are as familiar as this one, and the battle will not be to understand it so much as to take it to heart afresh. It really starts a new section, introducing themes and ideas that are explored more in 18:15-19:10, but to read it with the previous parable is quite striking. Both of course are parables about prayer, one showing the confidence we should have in prayer, the other the humility which should mark us in prayer. One is about praying for justice, the other about the need to pray for mercy. Both in a way concern God’s justice.
Notice the contrast between the two men, the two prayers, and the two verdicts. Beware leaving people thinking “God, I thank you that I am not like this Pharisee”, for that of course is to be exactly like him!