2 Chronicles 20:15

and he said, "Listen, all Judah, and you inhabitants of Jerusalem, and you king Jehoshaphat. Thus says the LORD to you, 'Do not be afraid, neither be dismayed by reason of this great multitude; for the battle is not yours, but God's.

1 Samuel 17:47

and that all this assembly may know that the LORD doesn't save with sword and spear: for the battle is the LORD's, and he will give you into our hand."

2 Chronicles 32:7-8

"Be strong and courageous, do not be afraid nor dismayed for the king of Assyria, nor for all the multitude who is with him; for there is a greater with us than with him.

Exodus 14:13-14

Moses said to the people, "Do not be afraid. Stand still, and see the salvation of the LORD, which he will work for you today: for the Egyptians whom you have seen today, you shall never see them again.

Deuteronomy 1:29-30

Then I said to you, "Do not dread, neither be afraid of them.

Deuteronomy 20:1

When you go forth to battle against your enemies, and see horses, chariots, a people more than you, you shall not be afraid of them; for the LORD your God is with you, who brought you up out of the land of Egypt.

Deuteronomy 20:4

for the LORD your God is he who goes with you, to fight for you against your enemies, to save you."

Deuteronomy 31:6

Be strong and courageous, do not be afraid, nor be scared of them: for the LORD your God, he it is who does go with you; he will not fail you, nor forsake you."

Deuteronomy 31:8

The LORD, he it is who does go before you; he will be with you, he will not fail you, neither forsake you: do not be afraid, neither be dismayed."

Joshua 11:6

The LORD said to Joshua, "Do not be afraid because of them; for tomorrow at this time, I will deliver them up all slain before Israel. You shall hamstring their horses and burn their chariots with fire."

Nehemiah 4:14

I looked, and rose up, and said to the nobles, and to the rulers, and to the rest of the people, "Do not be afraid of them. Remember the Lord, who is great and awesome, and fight for your brothers, your sons, and your daughters, your wives, and your houses."

Psalm 17:1-2

Hear, LORD, my righteous plea; Give ear to my prayer, that doesn't go out of deceitful lips.

Isaiah 41:10-16

Do not be afraid, for I am with you. Do not be dismayed, for I am your God. I will strengthen you. Yes, I will help you. Yes, I will uphold you with the right hand of my righteousness.

Isaiah 43:1-2

But now thus says the LORD who created you, Jacob, and he who formed you, Israel: "Do not be afraid, for I have redeemed you. I have called you by your name. You are mine.

Treasury of Scripture Knowledge

Summary

And he said, Hearken ye, all Judah, and ye inhabitants of Jerusalem, and thou king Jehoshaphat, Thus saith the LORD unto you, Be not afraid nor dismayed by reason of this great multitude; for the battle is not yours, but God's.

Bible References

The battle

2 Chronicles 32:8
With him is an arm of flesh; but with us is the LORD our God to help us, and to fight our battles." The people rested themselves on the words of Hezekiah king of Judah.
1 Samuel 17:47
and that all this assembly may know that the LORD doesn't save with sword and spear: for the battle is the LORD's, and he will give you into our hand."