As Helaman begins his charge to his sons, he begins with their names. In the ancient world names were considered as more powerful that simply a convenient identification. Names could alter the person, or at the very least were seen as a representation of the nature of the person. It is for this reason that Abram is changed to Abraham. The person did not change, but there was a change in the fundamental relationship of that person to God and to promises, a fundamental difference that was important enough that it became embodied in the name.
It is in this light that we should understand not only the naming of Nephi and Lehi, but this charge from Helaman to his sons. Helaman returns to the reasons for which his sons were named for these first progenitors. The intent was that the names would be evocative of the person of those early fathers. As Helaman notes: “and this I have done that when you remember your names ye may remember them; and when ye remember them ye may remember their works…” Helaman names his sons so that they are connected to the works of those first progenitors. Of course the reason for the emulation of the works is that both Lehi and Nephi are “good” in the sense that they were faithful representatives of God.