2 Chronicles 25:7
But there came a man of God to him, saying, O king, let not the army of Israel go with thee; for the LORD is not with Israel, to wit, with all the children of Ephraim. But there came a man of God to him, saying, O king, let not the army of Israel go with thee; for the LORD is not with Israel, to wit, with all the children of Ephraim.
The verse belongs to the record of Amaziah, the unstable and disloyal king of Judah, in the succession of the kings of Judah from Jehoshaphat to Zedekiah during the divided kingdoms of Judah and Samaria that closed in B.C. 586. A man of God came to him saying not to let the army of Israel go with him into battle and not to rely on it, because the LORD was not with Israel, that is, with all the children of Ephraim. The Israelites were idolatrous, so separating from them was the right course.
Though Amaziah had already paid a hundred talents to hire the men, he was told the Lord was able to give him much more than that loss. He followed the advice, went without the Israelite army, and won victory, showing that obedience to God is worth more than preserving an earthly investment. The history shows that doing duty brought blessing while departing from God brought strife and captivity and great loss, showing how different things might have been if men had remembered God. It is a historical lesson showing how God's principles work in real events, and how willing God was to turn to help His people when they sought Him with all the heart and how mightily He wrought for them.
God regards people who long to do His will, and no one with a heart set on doing His will is unnoticed by Him. Amaziah accepted prophetic counsel when it suited him but rejected it when it reproved his chosen course, illustrating the danger of following one's own counsel instead of heeding God's prophet. The warning shows that God's people should not join with those opposed to Him to advance a supposedly religious cause, such as alliances with unchristian forces in support of Sunday laws.