Amaziah's Reign and War With Israel
Like so many people, Amaziah, king of Judah, started off on the right track, but his initial acts soon faded away. Indeed, it is specifically mentioned that he did "everything as his father Joash had done" (2 Kings 14:3)—meaning that he followed the right example that Joash set early on. But he later follows the example of Joash in apostasy and resultant disaster.
His first action as king was to execute those who had murdered his father (2 Chronicles 24:25-26). In doing so, he followed what God had taught Israel through Moses by not killing the sons of the perpetrators for their fathers' crime (compare Deuteronomy 24:16).
Then, however, we see Amaziah starting to waver. Instead of relying on God (2 Chronicles 14:11; Jeremiah 17:5), he thought he could protect Judah by hiring mercenaries from Ephraim—but God is not limited to our human efforts (Mark 9:23). To his credit, Amaziah listened to a man of God who came to him with sound advice (2 Chronicles 25:7-10). God honored his obedience with victory—but his earlier lack of trust was to backfire on him. The mercenaries he dismissed took advantage of the armies being away and pillaged Judah's frontier towns.
Sadly, it all went downhill from there. At this point, Chronicles records an utterly unconscionable fact not mentioned in Kings. Instead of thanking God for his victory, Amaziah "brought the gods of the people of Seir [that is, of the Edomites, whom he'd just defeated], set them up to be his gods, and bowed down before them and burned incense to them" (2 Chronicles 25:14). This was totally irrational to the point of absurdity. "The futility of 'gods, which could not save their own people' should have been obvious, but men still worship that which is demonstrably inadequate"(Expositor's Bible Commentary, note on verse 15, emphasis added). It seems that Amaziah couldn't learn the lesson.
There was no way God would allow Amaziah to get away with such outrageous behavior, and He sent a prophet to correct the king. But Amaziah didn't want the advice. Rather, he became a victim of his own pride. Overconfident following his victory over the Edomites, and angry at the Israelite mercenaries who raided Judah's cities after his dismissal of them, Amaziah challenged Jehoash of Israel to a battle—a senseless undertaking as portrayed by Jehoash's fable, where he likens Amaziah to a thistle fighting a cedar of Lebanon. Yet Amaziah would not see reason—indeed, this development "came from God," we are told, as a way for Him to impose judgment (verse 20).
Judah lost the battle. And, more humiliating still, Amaziah was taken captive and treasures from the temple and the palace were taken as spoils of war. Biblical historian Eugene Merrill writes: "Amaziah himself narrowly escaped with his life. Why Jehoash spared him at all is a mystery, for he evidently took him back to Samaria as a prisoner (2 Kings 14:13-14) [after taking him to the plunder of Jerusalem (2 Chronicles 25:23-24)]. The answer may lie in the date of these events. Both the author of Kings and the chronicler stress that Amaziah outlived Jehoash by fifteen years (2 Kings 14:17; 2 Chronicles 25:25). This may be their oblique way of suggesting that Amaziah's release from Israelite control is to be tied in with the death of his captor" (Kingdom of Priests: A History of Old Testament Israel, 1987, p. 372). Merrill's explanation has Amaziah being released soon afterward—seeing the battle described here as occurring just before Jehoash's death. However, he also offers the possibility that the battle occurred 10 years prior to Jehoash's death (see p. 372 footnote).
In comparing all the biblical data on when the kings of this period reigned, the latter appears to be the case. This would mean that Amaziah was a captive of Israel for 10 years, during which time his son Uzziah (or Azariah) was elevated to the throne of Judah. Upon the death of Jehoash, Amaziah is evidently permitted to return to Judah, where he lives for 15 more years in a coregency with his son (see Edwin R. Thiele, The Mysterious Numbers of the Hebrew Kings,1983, pp. 113-116).