Luke 18:1

And He spake also a parable to them, to shew that men ought always to pray, and not to faint:

Philippians 4:6

Be anxious in nothing: but in every thing by prayer and supplication with thanksgiving let your requests be made known before God.

Colossians 4:2

Persevere in prayer, and be watchful in it, with thanksgiving.

Treasury of Scripture Knowledge

Summary

Because he hath inclined his ear unto me, therefore will I call upon him as long as I live.

Bible References

Therefore

Luke 18:1
And He spake also a parable to them, to shew that men ought always to pray, and not to faint:
Philippians 4:6
Be anxious in nothing: but in every thing by prayer and supplication with thanksgiving let your requests be made known before God.
Colossians 4:2
Persevere in prayer, and be watchful in it, with thanksgiving.