Luke 11:8-10
I tell you, even though he will not get up and give him something because he is a friend, yet because of his friend's persistence, he will [eventually] get up and give him whatever he needs.
Luke 18:1
Then Jesus told His disciples a parable for the purpose of showing them that they should pray continually and not become discouraged.
Ephesians 6:18
[Then] offer all kinds of prayers and requests in [harmony with] the Holy Spirit at all times, and be alert constantly in making requests for all the saints [i.e., God's holy people].
Colossians 4:2
Continue to pray regularly; stay alert and be thankful.
1 Thessalonians 5:17
Never stop praying.
James 5:16
So, confess your sins to one another, and pray for one another to be healed [from sin sickness]. The special request of a righteous person is empowered with [great] effectiveness.