Luke 18:1, 6-8

Then He spoke a parable to them, that men always ought to pray and not lose heart

Then the Lord said, “Hear what the unjust judge said. And shall God not avenge His own elect who cry out day and night to Him, though He bears long with them? I tell you that He will avenge them speedily. Nevertheless, when the Son of Man comes, will He really find faith on the earth?”