The book of Moroni most likely was written sometime between A.D. 400 and 421, at least 15 years after the beginning of the battle at Cumorah.
In Morm. 8:2-5, Moroni wrote that, as a result of that battle, the Nephites were destroyed, and that he remained "alone to write the sad tale of the destruction of my people."In the first verse of the book that bears his name, Moroni wrote, " . . . I had supposed not to have written more, but I have not as yet perished; and I make not myself known to the Lamanites lest they should destroy me."
According to the second verse in the first chapter of Moroni, he was not the only Nephite to have survived the battle at Cumorah. In that verse, he indicated the Lamanites continued to "put to death every Nephite that will not deny the Christ."
Was the Nephite nation annihilated? In A Companion to Your Study of the Book of Mormon, Daniel H. Ludlow quoted Hugh Nibley: "The Nephites were destroyed, we are told, but . . . what does the Book of Mormon mean by
destroyed'? The word is to be taken, as are so many other key words in the book, in its primary and original sense:To unbuild; to separate violently into its constituent parts; to break up the structure.' To destroy is to wreck the structure, not to annihilate the parts. . . .
"Only once in the Book of Mormon do we read of a case of annihilation, when we are specifically told that `every living soul of the Ammonihahites was destroyed' (Alma 16:9), where not only the social structure but each individual is undone."
Nibley pointed out that the Lord promised He would not utterly destroy the descendants of Lehi's youngest son, Joseph. (2 Ne. 3:3.) Also Nephi was told God "will not suffer that the Gentiles will utterly destroy the mixture of thy seed which are among thy brethren" (1 Ne. 13:30) even though the promises and fulfillment were that the Nephites should be "destroyed" (Eth. 8:21) and even though Moroni could write, ` . . . there is none, save it be Lamanites.' (Ether 4:3.)