Theme: Jesus Christ will return to bring justice; pray to the Father whilst you wait

“You shall not pervert the justice due to the sojourner or to the fatherless, or take a widow's garment in pledge, but you shall remember that you were a slave in Egypt and the Lord your God redeemed you from there; therefore I command you to do this. - Deuteronomy 24:17-18

But do not overlook this one fact, beloved, that with the Lord one day is as a thousand years, and a thousand years as one day. The Lord is not slow to fulfill his promise as some count slowness, but is patient toward you, not wishing that any should perish, but that all should reach repentance. - 2 Peter 3:8-9

Summary of Luke 17:20-18:8
This section of teaching focuses on the coming of the Son of Man. Mentioned in both the opening (17:20) and closing verse (18:8), Jesus tells his disciples what life will be like before his return (17:20-37), and encourages them how they are to behave in the midst of injustice and unrighteousness (18:1-8).

Does Jesus not know if there will be believers when he returns in glory?
The question asked by Jesus is not one of uncertainty and speculation. He wants to encourage his disciples to self-examination and reflection. He wants them to persevere to the end. Elsewhere the Bible is clear that there will be believers when the Son of Man returns in glory (cf. Matthew 24:44-46; Luke 12:37; 17:34,35; 1 Thessalonians 4:13-18).