Again Nephi addresses the three groups of people and equates their believing in Christ and his words with doing good (v. 9). The two go hand in hand. Mormon makes a similar equation as he ends his record nearly a thousand years later.
9 For behold, this is written for the intent that ye may believe that; and if ye believe that ye will believe this also; and if ye believe this ye will know concerning your fathers, and also the marvelous works which were wrought by the power of God among them (Mormon 7:9).
If they believe in Christ they will believe in Nephi’s (and his seed’s) words. They must believe in Nephi’s words because Christ is really their author (v. 10). That they are his words will be confirmed at the last day or the Second Coming, and when the words of Nephi will go to the lost tribes.
Once more Nephi exemplifies charity as he prays that many if not all will be saved in the kingdom of God.