The Amalekites were “Nephite apostates who lived in the land of Nephi among the Lamanites and who were noted for their ‘more wicked and murderous disposition than the Lamanites’ (Alma 43:6; 21:1–2 … ). The Book of Mormon does not supply any information concerning the origin of this group, but it does record some important details about their activities. The Amalekites, with the Lamanites and Amulonites, ‘built a great city, which was called Jerusalem’ (Alma 21:2). Many of them followed after the ‘order of the Nehors,’ and synagogues were built where they assembled to worship their God (Alma 21:4–6). They rejected the tradition of their Nephite fathers concerning the coming of Christ … (Alma 21:6–8)” (Largey, Book of Mormon Reference Companion, 44–45).
“Given the constraints of space on Mormon’s abridgment of the large plates, why would he devote so much time to a discussion of war? … Though the list below is by no means exhaustive, we might consider the following important lessons.
“1. The Christian’s attitude toward war. ‘War is basically selfish,’ President David O. Mckay stated. ‘Its roots feed in the soil of envy, hatred, desire for domination. Its fruit, therefore, is always bitter. … War impels you to hate your enemies. The Prince of Peace says, love your enemies. War says, curse them that curse you. The Prince of Peace says, pray for them that curse you. War says, injure and kill them that hate you. The risen Lord says, do good to them that hate you.’ …
“2. The importance of righteous military leaders. The Nephite military leaders were not bloodthirsty. They hated war and hated the thought of shedding the blood of their brethren … [and appointed] ‘(save it were in their times of wickedness) some one that had the spirit of revelation and also prophecy’ (3 Nephi 3:19) … .
“3. Our attitude toward constituted government. … The Lord has instructed us that Latter-day Saints in the United States are to be subject to the powers [of government]. Though some of Moroni’s actions might be offensive to the more pacifistic of this modern age, he acted in harmony with what he felt was his and others’ duty to God, even to the point of compelling dissenters to take up arms in support of the government during war (see Alma 51:15–16) … .
“4. The power and influence of a righteous home. Because righteousness was central to the maintenance of the government, proper training in the home, in the family setting, was absolutely necessary. This is illustrated beautifully in the lives of Helaman’s two thousand stripling warriors … .
“5. A person’s external circumstances need not determine his attitude or his faithfulness. One of the vital messages of the Book of Mormon is that one can remain untainted from the sins of the world, no matter what the extent of the degradation of the day … .
“6. Why God allows the righteous to be slain. War is ugly. Its effects are poignant and painful. Its reach is devastating. It rushes into premature death a great many of the sons and daughters of God … .
“7. A prophetic pattern of what is to come. Though it is not pleasant to entertain such a thought, it may be that the chapters on warfare have been preserved to prepare us for things to come” (McConkie and Millet, Doctrinal Commentary, 3:321–27).