What does Luke 18:27 mean?

This verse is the theme of the entire chapter.

In the parable of the persistent widow, God's elect put their faith in Him. They know their Father will willingly and quickly give them justice (Luke 18:1–8). What people barely offer, if ever, God gives freely.

In the parable of the Pharisee and the tax collector, the Pharisee espouses his own greatness. But heavenly mercy is reserved for those like the tax collector, who repents in humble faith (Luke 18:9–14). Where human arrogance results in a dead end, God's mercy breaks through.

When the disciples try to keep parents from bringing children to Jesus, He rebukes them. God opens His kingdom to those who know they are powerless, not those who think they deserve it (Luke 18:15–17).

Finally, here, a crowd learns that even someone bearing all the worldly signs of being a good person cannot earn eternal life. Only God saves (Luke 18:18–30). What human efforts could never do, God's love and mercy will accomplish. It is God who saves, not our works or goodness or sacrifices. It is God who gives us good works to do because it is He who saves (Ephesians 2:8–10).

Next, Jesus explains why God can give such mercy: because Jesus will go to the cross (Luke 18:31–34). Then a blind beggar proves that decorum is nothing compared to a bold, loud faith that God will save (Luke 18:35–43). God will reach into the heart of a rich man and show him his money is nothing compared to the spiritual riches of the kingdom of God. The young man of this verse is not willing, but Zacchaeus is (Luke 19:1–10).