2 Chronicles 20:15
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. 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.
The word was spoken to King Jehoshaphat together with all Judah and the inhabitants of Jerusalem when they stood terrified before a great hostile multitude. They had humbled themselves and asked God for help, and the Spirit gave the word through Jahaziel. Its central assurance is that they need not be afraid nor dismayed by reason of the great multitude, for the battle is not theirs but God's.
They were therefore to trust God and His prophets, to go out the next day, to stand firm, and to witness the salvation and deliverance of the Lord, with the promise that the Lord would be with them. They were to go forward in praise because victory had been promised to those who depend on Him. The same assurance applies whenever God's people face overwhelming danger and in every emergency today, that God will lead and deliver those who depend on Him. He is their strength and strong tower of defense, with all power and limitless resources.
They are therefore not to trust in princes nor to put fallible and erring human beings in the place of God. They are not to look at supposed impossibilities, for what appears impossible will make the victory all the greater. In doing battle for God there is to be no uncertainty, guesswork, worry, or momentary release from companionship with Jesus, for worry is unbelief. The Lord gives counsel to those who seek to know the mind of the Spirit, knowing human weakness and inability to overcome the powers of darkness in finite strength and knowing all the wiles of the devil.
He braces up the worker and gives the earnest seeker wisdom to do his part by committing everything in earnest trusting prayer and then trusting and believing without a shadow of doubt that He will do His part. The Captain of the Lord's host takes the field with all His heavenly intelligences, and the Lord God of hosts fights against satanic powers, doing the work and bringing glory to His own name. The work belongs to the Lord rather than to His servant, so the servant is to speak the truth in faith and love and leave the result with God. He is to rely on sustaining grace rather than becoming entangled in controversy and strife.