Luke 18:1
And he spoke a parable to them to this end, that men ought always to pray, and not to faint;
Nave's Topical Index—AKJV

Romans 12:12
Rejoicing in hope; patient in tribulation; continuing instant in prayer;
Nave's Topical Index—AKJV

Ephesians 6:18
Praying always with all prayer and supplication in the Spirit, and watching thereunto with all perseverance and supplication for all saints;
Nave's Topical Index—AKJV

Colossians 4:2
Continue in prayer, and watch in the same with thanksgiving;
Nave's Topical Index—AKJV

1 Thessalonians 5:17
Pray without ceasing.
Nave's Topical Index—AKJV