This part of 3 Nephi is a third-person abridgement-commentary by Mormon, who identified himself here in a traditional manner used in writing a letter or document. He declared himself to be “a disciple of Jesus Christ, the Son of God. I have been called of him to declare his word among his people, that they might have everlasting life” (v. 13). In good scribal style, he assures us that he knew that the record that he made was a just and a true record (v. 18). Notice also that this is an early statement by Mormon of his purpose in writing the Book of Mormon. On the Title Page, which is more familiar to most readers of the Book of Mormon, Moroni will eventually state the purpose of this entire book somewhat differently from his perspective.
Mormon also noted here that his record was to be kept according to the “will of God, that the prayers of those who have gone hence, who were the holy ones, should be fulfilled according to their faith (v. 14). What a mission, and how well he fulfilled it, even though he struggled because, as he says, there were many things which “according to our language, we are not able to write” (6:18). One wonders about the written language limitations Mormon apparently had to deal with.