Amaziah was not unlike his father; the light of testimony was burning but dimly now in Judah. He did what was right in the sight of the Lord, but not with a perfect heart. The murderers of his father he punished, and he gathered Judah together, reestablishing the army after the breakdown in the Syrian invasion. He formed no alliance with the idolatrous kingdom of his brethren of Israel to the north, but he did hire a hundred thousand of their soldiers, and this act brought a man of God to the king to tell him that the army of Israel should not be used, for the Lord was not with the children of Ephraim. If his mind was still, to use these men, God would make him fall before the enemy, for He has over to help and to cast down (verse 8).
Amaziah thought of the $200,000 (reckoned in American and Canadian money) that he had paid for the soldiers' services, but the man of God answered, "The Lord is able to give thee much more than this." How true! God enriches those who are losers in this world's things for His sake, if not in natural blessings, then in the far more valuable spiritual ones. The soldiers returned home in great anger, and presently attacked the nearer defenseless cities of Judah.
Amaziah led forth his people, and went to the valley of salt in the south, against the children of Seir, and defeated them in battle, and in this he may have been doing the will of God, but (such is man!) he brought the gods of the Edomites and set them up to be his gods, bowing down to them, and burning incense to them.
Thus did this privileged son of Abraham, David and Solomon! The anger of the Lord was kindled against him, but as usual He sent first the warning voice of a servant, a prophet, and that refused, judgment followed.
In pride, Amaziah sought battle with the king of Israel, and though advised by him to stay at home, he persisted, and he and his were routed in battle and fled. The victor brought his army to Jerusalem, and further humiliated Amaziah, whom he had captured, and broke down the wall for 400 cubits. All the gold and silver, and all the vessels found in the temple, and the treasures of the king's house, hostages also, the king of Israel carried away.
Amaziah died like his father, the victim of a conspiracy among his servants. God is not mocked.
Was he a believer ? Eternity will disclose.