Luke 11:8-10
I tell you, although he will not get up and give you any because he is your friend, yet because of your persistence he will get up and give you all your needs.
Luke 18:1
Now He told them the following story to show how necessary it is for people always to pray and never to give up:
Ephesians 6:18
Keep on praying in the Spirit, with every kind of prayer and entreaty, at every opportunity, be ever on the alert with perfect devotion and entreaty for all God's people,
Colossians 4:2
You must persevere in prayer and by this means stay wide awake when you give thanks.
1 Thessalonians 5:17
Never stop praying.
James 5:16
So practice confessing your sins to one another, and praying for one another, that you may be cured. An upright man's prayer, when it keeps at work, is very powerful.