2 Chronicles 25:1-13; 2 Chronicles 25:25-28
Amaziah succeeds his father Joash. On the whole he starts by doing what is right in the eyes of the LORD. "But not with a perfect heart," it is added (v. 2)! A perfect heart does not mean that there is no sin present, rather that it has a will which is determined to do just one thing: to please God by obeying Him (compare Philippians 3:15 with the verse which precedes it).
The first mistake: Amaziah goes to war against Edom and takes on one hundred thousand mercenaries from Israel to reinforce his army. Being reproved by a man of God, he gives up that idea and triumphs over his enemies. But then what a downfall! The Edomite idols find a place to dwell in Amaziah’s divided heart (see v. 14). And as it is impossible to serve both God and Mammon (Matthew 6:24; Luke 16:13), from that moment the LORD is no longer in his thoughts. Amaziah has turned away from Him (v. 27). If the Lord Jesus does not fill my whole heart, the Enemy knows what to put in the empty space.
Having suffered an embarrassing defeat at the hands of the king of Israel, poor Amaziah lives on for fifteen more years, after which he is killed without having shown any sign of repentance.