1 Nephi can be seen as the book of Lehi and his son Nephi. It even ends, "Wherefore, ye need not suppose that I and my father are the only ones that have testified" that the Holy One will reign and only those who are obedient to the commandments will dwell safely with him (22:24, 28, 31). But 2 Nephi continues on with the history of Nephi without his father. It begins with the final testament and death of Lehi, and then continues as Nephi, with the priestly help of his much younger brother Jacob, successfully establishes his people in the land of promise.
But this is the only place in the Book of Mormon where we have two books named after one person. We do not have a book of 1 Alma and another of 2 Alma, even though the book of Alma goes on for 63 chapters. The book of Alma could logically have been divided at the place in which Helaman became the leader of the church in chapter 45, but it was not. Here, in the case of Nephi, we have a single author, one man, who interrupted his record at the end of where chapter 22 now ends, suggesting that somehow the 22 chapters of 1 Nephi were intended to be read as a complete or unified record. Indeed, that composition has a coherent structure to it, drawing largely on certain repeated themes or motifs. At that point, Nephi carries on and creates the book of 2 Nephi, which has a very different purpose. In his first book, Nephi is getting out of the Old World, and in the second, he is getting established in the New. And there are other differences as well.
As we study the overall structures of these two books, the most important part of each book becomes clear. The crucial theme is often found at the center, and at the middle of 1 Nephi we find Nephi’s great vision, beginning in chapter 11, where he sees the birth of Christ, the condescension of Christ, the love of God. This is where Nephi says he does not "know the meaning of all things," but he does "know that [the Lord] loveth his children" (1 Nephi 11:17). I see this as the structural center of 1 Nephi. That is the main theme and message of this book. The center of 2 Nephi is the long quotation of Isaiah 2-14 as the third witness, together with Nephi and Jacob, of the testimony of Christ.
Then are other oft-repeated themes. In 1 Nephi, sometimes Nephi reinforces the idea of being his father’s successor. At the same time, we see the repeated struggles and spiritual degeneration of Laman and Lemuel. The similarities and contrasts in these stories help us see their underlying purposes, the main messages that Nephi wants us to get out of this. Notice how many things happened or are mentioned twice in 1 Nephi: (a) Nephi was tied up twice—once in the first half of the book when he and his brothers were returning from Jerusalem with Ishmael’s family, and later, a second time, on the ship, during their voyage to the promised land. (b) The daughters of Ishmael are mentioned twice, once in 1 Nephi 7 and again, later, when they marry the sons of Lehi and Zoram in 1 Nephi 16. (c) Brass is mentioned two times—plates of brass, and then the ball made of brass, called the Liahona. Both of these brass objects functioned as guides. (d) We also encounter two objects made of steel—Laban’s steel sword, and the steel bow that broke. The steel bow would not have been a bow made completely out of steel, but rather probably had steel strips or straps to reinforce or strengthen a wooden bow, giving it a little more spring. Such bows are called composite bows. Likewise, Laban’s sword was not completely made of steel either. It had a hilt made of gold, so both items were likely composites. Both were weapons; both functioned in the hand of the Lord to accomplish, in one case, life through death, and in the other case, life through hunting; and both became symbols of the divine right to lead or rule. And so on.
Although every element in 1 Nephi does not fit into a rigorously inverted or chiastic structure, many of its features counterbalance each other. Noticing these interconnections can help in seeing this book as a unified and purposeful narrative. Remember, 1 Nephi was not written as a journal that Nephi wrote as these events were going on. It is a purposefully selective, organized, coherent, and memorable retrospective account of what happened in his life. It looks back on how Lehi and his posterity reached the Promised Land, and it provides the backstory for why the Nephites ended up separating from their brethren, the Lamanites. Readers are then in a position to see how the hand of the Lord was involved in these people’s lives and how He will continue to give guidance and blessings to all who will come unto Him.
For a chiastic arrangement of 1 Nephi, see John W. Welch, ed., Chiasmus in Antiquity (Hildesheim, German: Gerstenberg, 1981), 199–200; see further, Noel B. Reynolds, "Nephi’s Outline," in Book of Mormon Authorship: New Light on Ancient Origins, ed. Noel B. Reynolds (Provo, UT: Religious Studies Center, Brigham Young University, 1982), 53–74.