Then Jesus told them a parable about their need to pray at all times and not lose heart:

Isaiah 40:31
But those who wait upon the LORD will renew their strength; they will mount up with wings like eagles; they will run and not grow weary, they will walk and not faint.

Isaiah 62:7
nor give Him any rest until He establishes Jerusalem and makes her the praise of the earth.

Luke 11:5
Then Jesus said to them, "Suppose one of you goes to his friend at midnight and says, 'Friend, lend me three loaves of bread,

Luke 11:8
I tell you, even though he will not get up to provide for him because of his friendship, yet because of the man's persistence, he will get up and give him as much as he needs.

2 Corinthians 4:1
Therefore, since God in His mercy has given us this ministry, we do not lose heart.

Ephesians 6:18
Pray in the Spirit at all times, with every kind of prayer and petition. To this end, stay alert with all perseverance in your prayers for all the saints.

And he spoke a parable to them to this end, that men ought always to pray, and not to faint;