Here is how the King James Version renders Luke 18:8.

Luke 18:8 KJV
8 I tell you that he will avenge them speedily. Nevertheless when the Son of man cometh, shall he find faith on the earth?

This makes it sound like all Yeshua wants is to find us faithful (devout) upon His return. However, the graphic below is an interlinear Greek-English translation, with the Strong’s numbers supplied. Notice how Strong’s renders NT:3588 as “the” prior to the word earth, but it is omitted prior to the word “faith”. Also notice also how it inverts the meaning of this passage.

Strong’s Hebrew Concordance tells us NT:3588 is the definite article “the.”

NT:3588 ho; including the feminine he (hay); and the neuter to; in all their inflections; the def. article; the (sometimes to be supplied, at others omitted, in English idiom):

Strong’s tells us we can add or omit this word as needed. However, Scripture tells us several times not to add or take away from Elohim’s words. For example.

Devarim (Deuteronomy) 4:2
2 “You shall not add to the word which I command you, nor take from it, that you may keep the commandments of Yahweh your Elohim, which I command you.”

If we restore the missing definite article, what we see is that Yeshua asked if He would truly find the faith on the earth, at His return.

Luke 18:8 KJV Corrected
8 “I tell you that He will avenge them speedily. Nevertheless when the Son of man cometh, shall He find the faith on the earth?”

This harmonizes with Jude 3.

Yehudah (Jude) 3
3 Beloved, while I was very diligent to write to you concerning our common salvation, I found it necessary to write to you exhorting you to contend earnestly for the faith which was once for all delivered to the saints.

So while Yeshua surely wants us to have faith, He also wants us to practice the faith He delivered once for all.