Many of the Nephites, as they heard the Lord speak of the fulfillment of the law of Moses, must have wondered whether the words and teachings of the previous Nephite/Lamanite prophets, as well as the Old World prophets whose teachings they had from the brass plates, were no longer relevant to them.
In these verses the Savior clearly states that the fulfillment of the law of Moses does not “destroy” the words of the previous prophets. There were yet many prophecies of these earlier prophets that were to be fulfilled, and the Savior’s ministry did not alter or “destroy ” them. In addition, the principles that had been previously taught were still true; but the practices associated with the law were no longer needed.
Covenants were not changed, but the manner in which they lived certain covenants was modified. In our own day, perhaps we, like the Nephites, wonder why and/or misunderstand the reason for changes in Church practices or organization. Elder Boyd K. Packer observed:
“There are those within the Church who are disturbed when changes are made with which they disagree or when changes they propose are not made. They point to these as evidence that the leaders are not inspired.... Changes in organization or procedures are a testimony that revelation is ongoing. While doctrines remain fixed, the methods or procedures do not.”
(CR, October 1989, p. 18.)