Josiah was credited as the king that restored true worship of the Lord to the people of Judah and Jerusalem. While his servants were preparing to restore the Temple from its damages, Hilkiah the priest found the Book of the Law inside, seemingly abandoned from disuse. He brought the Book to the king and read from it, and what he read made the king tear his clothes, realizing that the Lord's wrath is great against His people because they have not obeyed the words of that Book. Josiah's servants sought out Huldah the prophetess, who told them to tell Josiah that the Lord's words about His wrath will come true, but in regards to the king because he had humbled himself before the Lord when he heard, he will go to his rest in peace and not see the coming disaster in his lifetime.
It is from there that Josiah made a covenant before the Lord to follow Him and keep all His commandments, testimonies, and statutes wholeheartedly. He totally cleaned the Temple out of all its idols and implements that were made for pagan Gods, and removed the priests that burned incense to those gods on the high places. He removed the booths that were being used by the male temple prostitutes. He defiled Topeth, which is in the Valley of Ben Hinnom, a place being used for religious burnings of children. He removed the horses that were dedicated by the kings of Judah to the sun, and burned the chariots of the sun with fire. He defiled the high places that were east of Jerusalem on the Mount of Corruption that King Solomon had made to the pagan Gods. He destroyed the altar and the high place that was at Bethel and burned the wooden image. He took the bones of priests out of the tombs and burned them on the altar, fulfilling what a prophet of God had said in the days of King Jeroboam son of Nebat in:
- O altar, altar, thus saith the Lord; Behold, a child shall be born unto the house of David, Josiah by name; and upon thee shall he offer the priests of the high places that burn incense upon thee, and men's bones shall be burnt upon thee.
After his massive cleanup of all the idolatrous items and people, in the eighteenth year of his reign, King Josiah commanded the people of Judah to keep the Passover to the Lord their God as written in the Book of the Covenant.
Unfortunately, this revival didn't last, nor did it cause God to turn away His wrath upon His people. King Josiah confronted Pharaoh Necho as he was coming up out of Egypt to go against the king of Assyria at the Euphrates River. The Pharaoh tried to warn Josiah away, but Josiah didn't listen, and so he was slain by Necho in Megiddo. He was taken back to Jerusalem in a second chariot, where he was buried and the people mourned for him. After Josiah's death, the people made his son Jehoahaz king in his place and they soon fell away into idolatry again.