Luke 11:8-10
I tell you, even if he will not get up and give him some because he is his friend, yet because of his persistence he will rouse himself and give him all he needs.
Luke 18:1
He gave them an illustration to show that they must always pray and not give up,
Ephesians 6:18
Use every kind of prayer and entreaty, and at every opportunity pray in the Spirit. Be on the alert about it; devote yourselves constantly to prayer for all God's people
Colossians 4:2
Be persistent in prayer and wide awake about it when you give thanks.
1 Thessalonians 5:17
Never give up praying.
James 5:16
So confess your sins to one another and pray for one another, so that you may be cured. An upright man can do a great deal by prayer when he tries.