2 Kings 20 - 23

King Mosiah warned -

"...that because all men are not just it is not expedient that ye should have a king or kings to rule over you.
17 For behold, how much iniquity doth one wicked king cause to be committed, yea, and what great destruction!
18 Yea, remember king Noah, his wickedness and his abominations, and also the wickedness and abominations of his people. Behold what great destruction did come upon them; and also because of their iniquities they were brought into bondage." (Book of Mormon Mosiah 29:16 - 18)

After the righteous king Hezekiah had passed away, his son Manasseh becomes king. And becoming king at such a young, he fell captive to the influences of false and wicked priests of idolatry. And Mannasseh -

"...did that which was evil in the sight of the LORD, after the abominations of the heathen, whom the LORD cast out before the children of Israel." (Old Testament 2 Kings 21:2)

"...and Manasseh seduced them to do more evil than did the nations whom the LORD destroyed before the children of Israel." (Old Testament 2 Kings 21:9)

And that he caused Judah to -

"...hath done wickedly above all that the Amorites did, which were before him..." (Old Testament 2 Kings 21:11)

Even to the point that he slew the prophets -

"...shed innocent blood very much, till he had filled Jerusalem from one end to another..." (Old Testament 2 Kings 21:16)

In great contrast to Manasseh, Josiah (his grandson) became one of the most righteous and valiant of all the kings of Judah. It is during the reign of Josiah that an interesting thing happens that may tend to provide one explaination why Israel would so easily fall into idolotrous worship. While craftsmen were repairing the breaches of the temple, Hilkiah the high priest -

"...found the book of the law in the house of the LORD." (Old Testament 2 Kings 22:8)

And -

"...when the king had heard the words of the book of the law, that he rent his clothes.
12 And the king commanded Hilkiah the priest, and Ahikam the son of Shaphan, and Achbor the son of Michaiah, and Shaphan the scribe, and Asahiah a servant of the king's, saying,
13 Go ye, enquire of the LORD for me, and for the people, and for all Judah, concerning the words of this book that is found: for great is the wrath of the LORD that is kindled against us, because our fathers have not hearkened unto the words of this book, to do according unto all that which is written concerning us." (Old Testament 2 Kings 22:11 - 13)

It appears that the scriptures had been lost amongst the children of Israel for some time. It was only as Josiah heard these words that he recognized how far Judah had wandered from their covenants. The seriousness of this was apparent to Nephi as -

"...the Spirit said unto me again...It is better that one man should perish than that a nation should dwindle and perish in unbelief...And now, when I, Nephi, had heard these words, I remembered the words of the Lord which he spake unto me in the wilderness, saying that: Inasmuch as thy seed shall keep my commandments, they shall prosper in the land of promise.
15 Yea, and I also thought that they could not keep the commandments of the Lord according to the law of Moses, save they should have the law." (Book of Mormon 1 Nephi 4:12 - 15)

This was true with the Mulekites in that -

"...they had brought no records with them; and they denied the being of their Creator; and Mosiah, nor the people of Mosiah, could understand them." (Book of Mormon Omni 1:17)

So Josiah -

"...went up into the house of the LORD, and all the men of Judah and all the inhabitants of Jerusalem with him, and the priests, and the prophets, and all the people, both small and great: and he read in their ears all the words of the book of the covenant which was found in the house of the LORD." (Old Testament 2 Kings 23:2)

And they obeyed the book of the covenant for -

"...the king commanded all the people, saying, Keep the passover unto the LORD your God, as it is written in the book of this covenant.
22 Surely there was not holden such a passover from the days of the judges that judged Israel, nor in all the days of the kings of Israel, nor of the kings of Judah..." (Old Testament 2 Kings 23:21 - 22)

But as obedient and diligent as Josiah was -

"...the LORD turned not from the fierceness of his great wrath, wherewith his anger was kindled against Judah, because of all the provocations that Manasseh had provoked him withal." (Old Testament 2 Kings 23:26)