Luke 18:1

He also taught them by a parable that they must always pray and never lose heart.

Colossians 4:2

Be earnest and unwearied in prayer, being on the alert in it and in your giving of thanks.

Romans 12:12

full of joyful hope, patient under persecution, earnest and persistent in prayer.

Ephesians 6:18

Pray with unceasing prayer and entreaty on every fitting occasion in the Spirit, and be always on the alert to seize opportunities for doing so, with unwearied persistence and entreaty on behalf of all God's people,

1 Thessalonians 5:17

Be unceasing in prayer.

Philippians 4:6

Do not be over-anxious about anything, but by prayer and earnest pleading, together with thanksgiving, let your request be unreservedly made known in the presence of God.

Luke 21:36

But beware of slumbering; and every moment pray that you may be fully strengthened to escape from all these coming evils, and to take your stand in the presence of the Son of Man."

Luke 11:5-9

And He said to them, "Which of you shall have a friend and shall go to him in the middle of the night and say, "'Friend, lend me three loaves of bread;

2 Corinthians 4:1

Therefore, being engaged in this service and being mindful of the mercy which has been shown us, we are not cowards.

Galatians 6:9

Let us not abate our courage in doing what is right; for in due time we shall reap a reward, if we do not faint.

Colossians 4:12

Epaphras, who is one of yourselves, a bondservant of Jesus Christ, sends greetings to you, always wrestling on your behalf in his prayers, that you may stand firm--Christians of ripe character and of clear conviction as to everything which is God's will.

Hebrews 12:3-5

Therefore, if you would escape becoming weary and faint-hearted, compare your own sufferings with those of Him who endured such hostility directed against Him by sinners.

Treasury of Scripture Knowledge

Summary

And he spake a parable unto them to this end, that men ought always to pray, and not to faint;

General references

Bible References

And not

Galatians 6:9
Let us not abate our courage in doing what is right; for in due time we shall reap a reward, if we do not faint.
Hebrews 12:3
Therefore, if you would escape becoming weary and faint-hearted, compare your own sufferings with those of Him who endured such hostility directed against Him by sinners.

General references

Luke 11:10
For every one who asks, receives; and he who seeks, finds; and to him who knocks, the door shall be opened.