Jacob begins his sermon telling his audience that it will not be a pleasant sermon. Jacob is there to call them to repentance. He is performing his duties that their sins might not be accounted to his lack of proper instruction. He has been diligent in fulfilling the office of his calling, but now is weighed down, “with much more desire and anxiety for the welfare of your souls.”
Verses 4 and 5 form an interesting contrast. He first says that “ye have been obedient unto the word of the Lord,” but follows that with “ye are beginning to labor in sin.” That they were farther along than simply just beginning will become evident as he continues. If he is about to call them to repentance, why does he say that as yet they have been obedient?
The promise of the land is that the Nephites will be protected upon obedience. They have not been destroyed. Therefore, their obedience is at least sufficient to forego that destruction. Nephi was saddened by what he saw as the direction of his people, and Jacob confirms that they continue to head in the wrong direction. If they continue, then will the destruction come.