Alma 21:2 a great city, which was called Jerusalem
"This was a Lamanite city, built within the borders of the land of Nephi. Nephite apostates-the Amulonites and Amalekites-aided in its construction. Its inhabitants always warred against those sent to it with the message of salvation. It is listed among those cities destroyed at the time of Christ's death. 'Waters have I caused to come up in the stead thereof,' the Lord said, 'to hide their wickedness and abominations from before my face, that the blood of the prophets and the saints shall not come up any more unto me against them' (3 Nephi 9:7)." (McConkie and Millet, Doctrinal Commentary on the Book of Mormon, vol. 3, p. 152)
Alma 21:3-4 the Amalekites and the Amulonites were still harder
By this time in the Book of Mormon, the people are not divided on racial lines as much as religious and political lines. There is a great amount of mixing of Nephite and Lamanite blood. The Amulonites are the descendants of the priests of Noah who were half Nephite (fathers) and half Lamanite (mothers). The Amalekites are apostate Nephites. The story of their dissent from the Nephites is not given by Mormon. They are a different group than the Amlicites spoken of in Alma 2-3. Given that these Amulonites and Amalekites practiced religion after the order of the Nehors (a recent religious movement), the dissent of the Amalekites probably occurred not long before Aaron showed up (see Alma 1:15-16).
The story of these two groups is crucial to the book of Alma. It won't be long before we will be reading about the many, hard-fought wars between the Lamanites and Nephites. It is the Amulonites and Amalekites who are the instigators and main military leaders of the Lamanite armies. They become a perpetual thorn in the side of the Nephites. Of their wickedness, Mormon commented, And thus we can plainly discern, that after a people have been once enlightened by the Spirit of God, and have had great knowledge of things pertaining to righteousness, and then have fallen away into sin and transgression, they become more hardened, and thus their state becomes worse than though they had never known these things (Alma 24:30).
"Both of these groups of people believed in the 'order of the Nehors', and they were so hardened in wickedness that only one Amalekite and no Amulonites were converted by the four sons of Mosiah and their companions (Alma 23:14)." (Daniel Ludlow, A Companion to Your Study of the Book of Mormon, p.208)
"When the Prophet [Joseph Smith] had ended telling how he had been treated [by apostates], Brother Behunnin remarked; 'If I should leave this Church I would not do as those men have done: I would go to some remote place where Mormonism had never been heard of, settle down, and no one would ever learn that I knew anything about it.' The great Seer immediately replied: 'Brother Behunnin, you don't know what you would do. No doubt these men once thought as you do. Before you joined this Church you stood on neutral ground. When the gospel was preached good and evil were set before you. You could choose either or neither. There were two opposite masters inviting you to serve them. When you joined this Church you enlisted to serve God. When you did that you left the neutral ground, and you never can get back on to it. Should you forsake the master you enlisted to serve, it will be by the instigation of the evil one, and you will follow his dictation and be his servant.' He [further] emphasized the fact that a man or woman who had not taken sides either with Christ or Belial could maintain a neutral position, but when they enlisted under either the one or the other they left the neutral ground forever." (Juvenile Instructor, Aug. 15, 1892, p. 492 as taken from Latter-day Commentary on the Book of Mormon compiled by K. Douglas Bassett, p. 228)
Alma 21:6 How knowest thou that we are not a righteous people? Behold, we have built sanctuaries, and we do...worship God
This is one of Satan's most effective arguments. As missionaries knock on doors, they are frequently told, "we have a religion, we have no need of your Book of Mormon." In so saying, the individual is often using this as an excuse to dismiss the new message. To them, having a religion is like having a car, a family, or a dog-it doesn't matter what kind it is as long as you have one. For years, the missionaries in Western Europe have struggled because the people there have felt like the Amalekites, saying, in effect, "we have a religion, we have no need of yours."
Satan would much rather have people believe in a religion which teaches that all are saved than that they have no religion at all. Those without religion often turn to God at some point, looking for answers to the meaning of life. A perfunctory, superficial religion, on the other hand, fosters spiritual complacency and keeps the individual from searching for more. Such is the religion of the Amalekites.
Neal A. Maxwell
"Therefore, as Aaron entered into one of their synagogues to preach unto the people, and as he was speaking unto them, behold there arose an Amalekite and began to contend with him, saying: What is that thou hast testified? Hast thou seen an angel? Why do not angels appear unto us? Behold are not this people as good as thy people? (Alma 21:5.)
We also see rationalization in the raw...Likewise open to plain view are the consequences of lapsed faith:
"'And thus we can plainly discern, that after a people have been once enlightened by the Spirit of God, and have had great knowledge of things pertaining to righteousness, and then have fallen away into sin and transgression, they become more hardened, and thus their state becomes worse than though they had never known these things.' (Alma 24:30.)
"We see variations in disbelievers, such as the paradox of some who believe vaguely but whose beliefs are not connected with their daily behavior. Some assume that the god they worship is a very permissive as well as passive god.
"Empty homage to a passive deity inevitably results in a permissive laity, as Alma explains: 'Now this was the tradition of Lamoni, which he had received from his father, that there was a Great Spirit. Notwithstanding they believed in a Great Spirit, they supposed that whatsoever they did was right.' (Alma 18:5.)
"We can better understand, therefore, why the adversary is anxious that people not be given those particularized saving truths that pertain to the past, present, and future. In the Book of Mormon we see several incidents of people who strayed and faltered because of their proud provincialism, and who then stoutly maintained that they could not know that which is to come. One example is the Zoramites, who, Alma said, 'did offer up, every man, the self-same prayer unto God, thanking their God that they were chosen of him, and that he did not lead them away after the tradition of their brethren, and that their hearts were not stolen away to believe in things to come, which they knew nothing about.' (Alma 31:22.)
"How fascinating to see adherence to a false religion in which superficial ritual, proud contentment, and a haughty rejection of prophecy were so adroitly combined! Sanctioned agnosticism can be very insistent on its own orthodoxy." (Plain and Precious Things, pp. 66-67)
Alma 21:16 they went forth whithersoever they were led by the Spirit of the Lord
How many prayers have been offered on behalf of the missionaries that they might be led to those who are searching after the truth? The missionaries themselves are praying for that same blessing, but it takes some real spiritual courage to depend wholeheartedly on the Spirit. A good missionary, like Aaron, must know how to be led by the Spirit.
Harold B. Lee
"I must go on many occasions, as did Nephi of old, being led by the spirit, not knowing beforehand the things which I should do (1 Ne 4:6). Yes though the night be dark, 'I do not ask to see the distant scene-one step [is] enough for me.'" (Conference Report, Apr. 1970, pp. 125-6)
Harold B. Lee
"Walk to the edge of the light, and perhaps a few steps into the darkness, and you will find that the light will appear and move ahead of you." (Boyd K. Packer: A Watchman on the Tower, p. 138)
Wilford Woodruff
"I went one evening to fill an appointment in the Town Hall, at the town of Hanley. There was a very large congregation, and I had appointments out for two or three weeks in that town and adjacent villages. As I went to take my seat the Spirit of the Lord came upon me and said to me, 'this is the last meeting you will hold with this people for many days.' I was surprised, because I did not know, of course what the Lord wanted me to do. I told the assembly when I rose, 'This is the last meeting I shall hold with you for many days.' They asked me after meeting where I was going. I told them I did not know. I went before the Lord in my closet and asked him where he wished me to go, and all the answer I could get was to go to the South. I got into a stage and rode eighty miles south, as I was led by the Spirit of the Lord. The first man's house I went into was John Benbow's...and I told him that the Lord had sent me to that place. But without wishing to dwell on this subject particularly I will say that I learned that there were six hundred people there, under Elder Kington, called 'United Brethren,' and that they had been praying to the Lord for guidance in the way of life and salvation. Then I knew why the Lord had sent me to that place-he had sent them what they had been praying for. I commenced preaching the Gospel to them, and I also commenced baptizing, Elder Pitt being among the first who was baptized by me into this Church and kingdom. The first thirty days after I arrived there I had baptized forty-five preachers, which flung nearly fifty preaching places, licensed by law, into my hands; and out of the six hundred belonging to Elder Kington's body all were baptized but one in seven months' labor. I brought eighteen hundred into the Church in that mission, and I will say that the power of God rested upon me and upon the people." (Journal of Discourses, vol. 15, p. 344)
Alma 21:21 he did teach them many things
The Book of Mormon has many stories of recent converts becoming great missionaries. Lamoni, Amulek, and even Zeezrom become great instruments in the hand of the Lord. Lamoni's ability to teach his people is key. The Lamanites are naturally suspicious of the Nephites and they are much less likely to listen to Ammon without the testimony of someone they trust. Lamoni provides than much needed second witness.
Alma 21:22 the liberty of worshiping the Lord their God according to their desires
Religious liberty under a monarchy is a rare phenomenon in the history of the world. The royal history of England is the best example of incredible conflict over religion. Yet Lamoni uses no coercion. He teaches his subjects the gospel but explains that they are free to worship according to their desires.
Brigham Young
"It is a love of liberty which inspires my soul-civil and religious liberty to the whole of the human race...I ask, Did I ever exercise any compulsion over any man? Did I not give him the liberty of disbelieving any doctrine [that] I have preached?" (Hugh Nibley, Brother Brigham Challenges the Saints, pp. 518-9)