Exodus 17:11

As long as Moses held up his hands, Israel would win, but as soon as he put his hands down, the Amalekites would start to win.

1 Timothy 2:8

I want the men in every place to pray, lifting up holy hands, without anger or argument.

James 5:16

Confess therefore your sins one to another, and pray one for another, that you may be healed. The prayer of a righteous man helps much.

Psalm 56:9

Then my enemies will turn back in the day when I call. This I know, that God is for me!

Luke 18:1

He spoke an illustration to them emphasizing the need to pray and not become tired:

Treasury of Scripture Knowledge

Summary

And it came to pass, when Moses held up his hand, that Israel prevailed: and when he let down his hand, Amalek prevailed.

Bible References

General references

Psalm 56:9
Then my enemies will turn back in the day when I call. This I know, that God is for me!
Luke 18:1
He spoke an illustration to them emphasizing the need to pray and not become tired:
1 Timothy 2:8
I want the men in every place to pray, lifting up holy hands, without anger or argument.
James 5:16
Confess therefore your sins one to another, and pray one for another, that you may be healed. The prayer of a righteous man helps much.