Luke 11:8-10
I say to you, even if he will not, rising up, give to him because of his being his friend; yet, because of his importunity, he, rousing himself, will give him as many as he needs.
Luke 18:1
And He spake a parable to them, to the end that they ought always to pray, and not to faint;
Ephesians 6:18
with all prayer and supplication praying at every opportunity in the Spirit, and watching thereunto in all perseverance and supplication for all the saints;
Colossians 4:2
Persevere in prayer, watching therein with thanksgiving;
1 Thessalonians 5:17
pray without ceasing.
James 5:16
Confess, therefore, your sins one to another, and pray for one another, that ye may be healed. A righteous man's inwrought supplication avails much.