Luk 18:1 Then He spoke a parable to them, that men always ought to pray and not lose heart,
Jesus speaks of this parable to help men grasp the concept of having keys to the kingdom and to always use it. That prayer unlocks the doors of heaven, however there is work involved and that work requires persistence without losing heart.
Jesus speaks in a clear manner that no one is exempt from praying and should already be doing it however hard it is. It’s an honor that God the just judge of the world stops to hear our prayers. This thought should make us not lose heart.
Persistence in prayer is requisite to making it effectual. It was Augustine who said “God reserves for thee that which he is slow to give thee, that thou mayest learn to entertain a supreme desire and longing for it.” Man should therefore pray as often as he has an opportunity. He should be constant and diligent at the throne of grace, and continue putting up his requests to God. Though some answers may delay to return, he should not faint because God is hearing and storing every prayer he offers. Psa 27:13-14 “13 I would have lost heart, unless I had believed That I would see the goodness of the Lord In the land of the living. 14 Wait on the Lord; Be of good courage, And He shall strengthen your heart;Wait, I say, on the Lord!”