First Nephi 16:39

And it came to pass that the Lord was with us, yea, even the voice of the Lord came and did speak many words unto them, and did chasten them exceedingly; and after they were chastened by the voice of the Lord they did turn away their anger, and did repent of their sins, insomuch that the Lord did bless us again with food, that we did not perish.

Isn't it interesting that despite the fact that Laman and Lemuel are in total rebellion and are threatening murder, God still speaks to them. They get to hear the voice of God, albeit in chastisement, whereas even the most righteous among us rarely get such a privilege. When the brothers eventually fall completely out of grace, they fall a long ways. 

Sin is a mistake; but iniquity is a constant choice to sin. The brothers will eventually stop turning away their anger and repenting. Their knowledge of God will turn to their everlasting condemnation.

We also read in this verse the continuing theme of the Book of Mormon: repentance, obedience and humility bring prosperity. It is a winning formula.