1 Samuel 1:12
And it came to pass, as she continued praying before LORD, that Eli noticed her mouth.
Luke 11:8-10
I say to you, though he will not give him, after getting up, because he is his friend, yet because of his persistence, having awaken, he will give him as many as he needs.
Luke 18:1
And he also spoke a parable to them about it being necessary to always pray, and not to give up,
Ephesians 6:18
praying through every prayer and entreaty at every time in spirit, and being alert in this same thing in all perseverance and entreaty for all the sanctified,
Colossians 4:2
Continue in prayer, being vigilant in it with thankfulness.
1 Thessalonians 5:17
Pray without ceasing.
James 5:16
Confess ye the trespasses to each other, and pray for each other so that ye may be healed. A working supplication of a righteous man is very powerful.