One of the great revivals in the Old Testament took place when the servants of King Josiah found the lost Book of the Law (The portions of the Bible which had been given up to that point in history). It is presumed that Josiah’s wicked grandfather Manasseh had hidden the Word of God so that it might be as far away from him and the people as possible.
When the king [Josiah] heard the words of the Book of the Law, he tore his clothes. And the king commanded Hilkiah the priest, and Ahikam the son of Shaphan, and Achbor the son of Micaiah, and Shaphan the secretary, and Asaiah the king’s servant, saying, “Go, inquire of the LORD for me, and for the people, and for all Judah, concerning the words of this book that has been found. For great is the wrath of the LORD that is kindled against us, because our fathers have not obeyed the words of this book, to do according to all that is written concerning us.”
– 2 Kings 22:11-13
Josiah knew God expected His people “to do according to all that is written.” Josiah committed himself to this task. First, he read all of God’s words to all the men, women, boys, and girls of Jerusalem (2 Kings 23:2). Then he systematically went through the entire land of Israel, tearing down the high places, and removing any method of worship which was not commanded in the Book (2 Kings 23:4-20). The priests who had worshipped using methods contrary to the Book were executed (2 Kings 23:20). Josiah then called all the people to worship God correctly.
And the king commanded all the people, “Keep the Passover to the LORD your God, as it is written in this Book of the Covenant.” For no such Passover had been kept since the days of the judges who judged Israel, or during all the days of the kings of Israel or of the kings of Judah. But in the eighteenth year of King Josiah this Passover was kept to the LORD in Jerusalem.
When I first read this, I didn’t believe it. The year is approximately 620BC. The period of the Judges was 1350-1100BC. The people of Israel had not worshipped God through the Passover celebration for over 500 years! God had commanded the people of Israel to worship Him through this particular celebration.
Because Josiah made the proper worship of God his top priority, God says that he stands apart from all kings before him and all kings after him.
Moreover, Josiah put away the mediums and the necromancers and the household gods and the idols and all the abominations that were seen in the land of Judah and in Jerusalem, that he might establish the words of the law that were written in the book that Hilkiah the priest found in the house of the LORD. Before him there was no king like him, who turned to the LORD with all his heart and with all his soul and with all his might, according to all the Law of Moses, nor did any like him arise after him.
– 2 Kings 23:21-25
God takes His worship seriously. He tells us in the pages of Scripture the manner and methods we are to use to worship Him rightly.