Luke 18:1

Then he told them a parable, to show that they ought always to pray and not lose heart.

Philippians 4:6

Do not be anxious about anything, but in everything by prayer and supplication with thanksgiving let your requests be made known to God.

Colossians 4:2

Devote yourselves to prayer, being 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
Then he told them a parable, to show that they ought always to pray and not lose heart.
Philippians 4:6
Do not be anxious about anything, but in everything by prayer and supplication with thanksgiving let your requests be made known to God.
Colossians 4:2
Devote yourselves to prayer, being watchful in it with thanksgiving.