These comparisons are important, not just as evidence of the intricate internal consistency within the Book of Mormon text. This also serves to demonstrate that prophets benefitted greatly from studying the words of former prophets. Likewise, we should treasure up the scriptures and liken them to ourselves.
In Helaman 5:6-8, we read:
6 Behold, my sons, I desire that ye should remember to keep the commandments of God; and I would that ye should declare unto the people these words. Behold, I have given unto you the names of our first parents who came out of the land of Jerusalem; 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; and when ye remember their works ye may know how that it is said, and also written, that they were good.
7 Therefore, my sons, I would that ye should do that which is good, that it may be said of you, and also written, even as it has been said and written of them.
8 And now my sons, behold I have somewhat more to desire of you, which desire is, that ye may not do these things that ye may boast, but that ye may do these things to lay up for yourselves a treasure in heaven, yea, which is eternal, and which fadeth not away; yea, that ye may have that precious gift of eternal life, which we have reason to suppose hath been given to our fathers.
This is a clear reference to 2 Nephi 33:
4 And I know that the Lord God will consecrate my prayers for the gain of my people. And the words which I have written in weakness will be made strong unto them; for it persuadeth them to do good; it maketh known unto them of their fathers; and it speaketh of Jesus, and persuadeth them to believe in him, and to endure to the end, which is life eternal.
Both passages mention three elements in close proximity:
- Remembering the fathers.
- Good works (keep in mind the name Nephi has reference to good/fair in the Egyptian language).
- Eternal life.