Luke 11:8-10
I say to you, Although he will not arise and give him, because he is his friend, yet, on account of his importunity, he will arise and give him as many as he needs.
Luke 18:1
And he spoke a parable to them, that they ought always to pray, and not to become weary,
Ephesians 6:18
praying with all prayer and supplication, at all times, in the Spirit; and to this end being watchful in all perseverance, and supplication for all the saints:
Colossians 4:2
Persevere in prayer, and be watchful in the same with thanksgiving;
1 Thessalonians 5:17
pray without ceasing;
James 5:16
Confess your faults one to another, and pray for one another, that you may be restored to health: the fervent prayer of a righteous man avails much.