Figure Analysis
Josiah starts off as a child king, and later becomes a teen king—sounds like a sitcom, right? But it isn't until adulthood that, in the process of ordering some temple repairs, Josiah has a chance to read the recently discovered "Book of the Law" (probably The Book of Deuteronomy), which the head priest Hilkiah finds. Josiah realizes they've been worshipping God all wrong and totally reverses the polytheistic policies of his granddad, the wicked king Manasseh.
Reversing these policies involves killing a lot of people and destroying a lot of stuff. High places, sacred poles, sacred pillars, various Baal-themed memorabilia—it's all gotta go. To provide an example:
Moreover, Josiah removed all the shrines of the high places that were in the towns of Samaria, which kings of Israel had made, provoking the Lord to anger; he did to them just as he had done at Bethel. He slaughtered on the altars all the priests of the high places who were there, and burned human bones on them. Then he returned to Jerusalem. (2 Kings 23:19-20)
Hulk Smash! (But, You Know, For God)
See? He's virtuous—yet, also really violent, like a Clint Eastwood character or something. We guess you could say Josiah's reign is a series of big "Hulk Smash!" moments—if for the greater good (his name means "Healed by God").
But despite being the first king to celebrate Passover practically since Moses—something not even David managed to do—Josiah's reforms aren't going to save all of Judah. The prophetess Huldah tells Josiah that God will have mercy on him, but everyone else is still going to pay their penalty for their evil ways. And after Josiah is killed by the Pharaoh Neco, that's exactly what happens.