Below are some Bible verses that talk about persistence in prayer. Note that when a loving God commands you to pray, it’s a sort of promise that he would answer.
“Pray hard and long. Pray for your brothers and sisters. Keep your eyes open. Keep each other’s spirits up so that no one falls behind or drops out.” Eph. 6:18 MSG
“Don’t be weary in prayer; keep at it; watch for God’s answers, and remember to be thankful when they come.” Col.4:2 LB
“O Jerusalem, I have set intercessors [lit. watchmen] on your walls who shall cry to God all day and all night for the fulfillment of his promises. Take no rest, all you who pray, and give God no rest until he establishes Jerusalem and makes her respected and admired throughout the earth.” Isaiah 62:6-7 LB
“O Jerusalem, I have posted watchmen on your walls; they will pray day and night, continually. Take no rest, all you who pray to the Lord. 7Give the Lord no rest until he completes his work, until he makes Jerusalem the pride of the earth.” Isaiah 62:6-7 NLT
“With this in mind, we constantly pray for you, that our God may make you worthy of his calling, and that by his power he may bring to fruition your every desire for goodness and your every deed prompted by faith. 12 We pray this so that the name of our Lord Jesus may be glorified in you, and you in him, according to the grace of our God and the Lord Jesus Christ.” 2 Thessalonians 1:11-12 NIV
“Be persistent in prayer, and keep alert as you pray, giving thanks to God. 3 At the same time pray also for us, so that God will give us a good opportunity to preach his message about the secret of Christ. For that is why I am now in prison. 4 Pray, then, that I may speak, as I should, in such a way as to make it clear. 5 Be wise in the way you act toward those who are not believers, making good use of every opportunity you have. 6 Your speech should always be pleasant and interesting, and you should know how to give the right answer to everyone.” Colossians 4:2-6 GNT
” Pray without ceasing;” 1 Thess. 5:17
“One day Jesus told his disciples a story to show that they should always pray and never give up. 2 “There was a judge in a certain city,” he said, “who neither feared God nor cared about people. 3 A widow of that city came to him repeatedly, saying, ‘Give me justice in this dispute with my enemy.’ 4 The judge ignored her for a while, but finally he said to himself, ‘I don’t fear God or care about people, 5 but this woman is driving me crazy. I’m going to see that she gets justice, because she is wearing me out with her constant requests!’” 6 Then the Lord said, “Learn a lesson from this unjust judge. 7 Even he rendered a just decision in the end. So don’t you think God will surely give justice to his chosen people who cry out to him day and night? Will he keep putting them off? 8 I tell you, he will grant justice to them quickly! But when the Son of Man returns, how many will he find on the earth who have faith?” Luke 18:1-8 NLT
“Then, teaching them more about prayer, he used this story: “Suppose you went to a friend’s house at midnight, wanting to borrow three loaves of bread. You say to him, 6 ‘A friend of mine has just arrived for a visit, and I have nothing for him to eat.’ 7 And suppose he calls out from his bedroom, ‘Don’t bother me. The door is locked for the night, and my family and I are all in bed. I can’t help you.’ 8 But I tell you this—though he won’t do it for friendship’s sake, if you keep knocking long enough, he will get up and give you whatever you need because of your shameless persistence. 9 “And so I tell you, keep on asking, and you will receive what you ask for. Keep on seeking, and you will find. Keep on knocking, and the door will be opened to you. 10 For everyone who asks, receives. Everyone who seeks, finds. And to everyone who knocks, the door will be opened. 11 “You fathers—if your children ask for a fish, do you give them a snake instead? 12 Or if they ask for an egg, do you give them a scorpion? Of course not! 13 So if you sinful people know how to give good gifts to your children, how much more will your heavenly Father give the Holy Spirit to those who ask him.” Luke 11:5-13 NLT
“Don’t worry about anything; instead, pray about everything. Tell God what you need, and thank him for all he has done.” Phil 4:6 NLT
“Do not be anxious about anything, but in everything by prayer and supplication with thanksgiving let your requests be made known to God.” Phil 4:6 ESV
“Rejoice in hope, be patient in tribulation, be constant in prayer.” Romans 12:12 ESV
“So he left them and went away once more and prayed the third time, saying the same thing.” Matt. 26:44 NIV
“They all joined together constantly in prayer, along with the women and Mary the mother of Jesus, and with his brothers.” Acts. 1:14 NIV
“I urge you, brothers and sisters, by our Lord Jesus Christ and by the love of the Spirit, to join me in my struggle by praying to God for me.” Rom. 15:30 NIV
“Do not deprive each other except perhaps by mutual consent and for a time, so that you may devote yourselves to prayer.” 1 Cor. 7:5
“And pray in the Spirit on all occasions with all kinds of prayers and requests. With this in mind, be alert and always keep on praying for all the Lord’s people.” Ephesians 6:18 NIV
“He [Epaphras] is always wrestling in prayer for you, that you may stand firm in all the will of God, mature and fully assured.” Col. 4:12