Luke 18:1, 6-8

ALSO [Jesus] told them a parable to the effect that they ought always to pray and not to turn coward (faint, lose heart, and give up).

Then the Lord said, Listen to what the unjust judge says! And will not [our just] God defend and protect and avenge His elect (His chosen ones), who cry to Him day and night? Will He defer them and delay help on their behalf? I tell you, He will defend and protect and avenge them speedily. However, when the Son of Man comes, will He find [persistence in] faith on the earth?