We see the life of Josiah In 2 Kings 22-23 and 2 Chronicles 34, an unlikely good king with a corrupt father and an exorbitantly corrupt grandfather.Though he had no biblical upbringing, the bible says he was the greatest king that the nation of Israel had seen.
2 Kings 23:25 ESV
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.
A king who grew up without knowing the law of the lord, but who had covenanted his heart to obey the very little law of the lord that he knew. This pleased the Lord. To reveal to Josiah his full counsel, he orchestrated the finding of the book of the law within the temple.
Many people are still waiting for the lord to reveal his will, without obeying the already revealed will of the Lord. He prefers a quick and simple obedience!!
Only to them does the Lord share his heart as to what further needs to be done.