After explaining how the Nephites should baptize Jesus continues his explanation by saying,
28 And according as I have commanded you thus shall ye baptize. And there shall be no disputations among you, as there have hitherto been; neither shall there be disputations among you concerning the points of my doctrine, as there have hitherto been....
40 And whoso shall declare more or less than this, and establish it for my doctrine, the same cometh of evil, and is not built upon my rock; (3 Nephi 11:28,40)Again there is the admonition that there should be no disputations and also a warning that if anyone adds to the doctrine, or takes away from it certain critical points, then those people are not building upon the rock of Christ, but on a sandy foundation that cannot weather the storms of life and temptation.
There may have been some question in some Nephites' minds whether or not baptism was even necessary. Approximately 34 years previous to this event when the sign of Christ's birth was given there were some who had insisted that the Law of Moses was fulfilled and that the Nephites no longer needed to keep it (see 3 Nephi 1:24-25). It is possible that there may have been a similar dispute at that time. The assumption that baptism was no longer required may have seemed obvious to many Nephites since they were all aware of the fact that the Law of Moses had been declared fulfilled (see 3 Nephi 9:16-20). The issue in their minds may have been that baptism, according to their understanding, was part of the Law of Moses, and thus they no longer needed to practice baptisms.
There also may have been some discussion about the actual mechanics of baptism, such as what needed to be said and other things. All these questions were answered by Jesus in his explanation of his doctrine. All of these possibilities that I have mentioned so far involve things that would have taken away from the ordinance of baptism but in verse 40 Jesus mentioned that "whoso shall declare more or less than this, and establish it for my doctrine, the same cometh of evil" (emphasis added). In other words, the possibilities that I have presented of what was causing contention all fall under the "less" category, so now the question is, what were some Nephites proposing that fell under the "more" category?
For one such possibility let us look into references to "altars" in the Book of Mormon. (What to altars have to do with baptism you ask? Just wait and see.)
In the Book of Mormon there are several references to sacrifices. Lehi and Nephi offered sacrifice. King Benjamin offered sacrifice. Sacrifice plays an important part in some doctrinal sermons. The Nephites were commanded by Jesus to stop sacrifices by the shedding of blood. But despite all these references to sacrifices, which presumably happened on an altar, there are only four references to altars in the Book of Mormon. The first refers to an altar built by Lehi after leaving Jerusalem. The second reference comes from a quote of a vision by Isaiah. The last two references come from parts of the text in Alma where Mormon is explaining or commenting on the results of the missionary endeavors of Alma the Younger and the sons of Mosiah. It seems that Mormon is simply mentioning the altars almost in passing, like we would mention a pulpit or the pews in a chapel.
The first reference in Alma comes in chapter 15, which reads:
17 Therefore, after Alma having established the church at Sidom, seeing a great check, yea, seeing that the people were checked as to the pride of their hearts, and began to humble themselves before God, and began to assemble themselves together at their sanctuaries to worship God before the altar, watching and praying continually, that they might be delivered from Satan, and from death, and from destruction— (Alma 15:17)The second reference is in chapter 17:
4 And [the sons of Mosiah] had been teaching the word of God for the space of fourteen years among the Lamanites, having had much success in bringing many to the knowledge of the truth; yea, by the power of their words many were brought before the altar of God, to call on his name and confess their sins before him. (Alma 17:4)The references in Alma to altars are so unremarkable that most people pass over them without thought. In the second reference, many people would read it and think that Mormon was waxing poetic when he said that the Lamanites "were brought before the altar of God". But if we return to the previous reference we read that the people began to assemble in their sanctuaries, where their sacrifices were presumably performed, "to worship God before the altar".
From this passage we can learn a little about the layout of the Nephite's (and later the converted Lamanite) sanctuaries. In their sanctuary where they met to worship there was, apparently, an altar much in the same way our church buildings have pulpits (this concept of an altar at the front of a church is not so confusing for Catholics, Orthodox and other similar creedal Christians, it's just unfamiliar to those of us who grew up in a Protestant influenced church culture). The exact size and configuration of the altar is not clear, but it may have been big enough for a single person to go stand on top of it (hmmm...suddenly the Rameumptom doesn't seem to come entirely out of left field, still imagine how surprised you might be if you walked into a church building and you find that the members of the congregation took turns standing on top of the pulpit, or sacrament table, and shouting out a memorized prayer at the top of their lungs).
The verse in chapter 15 simply calls it "the altar", but in chapter 17 it is referred to as "the altar of God". In Nephite phraseology saying that someone was brought "before the altar" may have been the equivalent of us saying we "filled the pews". The verse in chapter 15 merely states that the people "began to assemble themselves...before the altar" where they prayed, taught and exhorted each other, and made sure that they were all kept in the way.
But in chapter 17 the recently converted Lamanites were brought, "by the power of [the sons of Mosiah's] words" before the "altar of God" where they "[called] on his name and [confessed] their sins before him." This sounds like something a little more formal, organized and dramatic than a simple church meeting. We read elsewhere that the converted Lamanites had made a covenant, a very public covenant that the Nephites knew about, and apparently this covenant was made before the "altar of God", so it was a very serious thing.
When the converted Lamanites came to the land of Zarahemla being lead by the sons of Mosiah, one of the stipulations that the Nephites may have insisted on before accepting them and giving them the land of Jershon may have been that the people of Ammon must appear before "the altar of God" and "call on his name and confess their sins before him" and covenant to never take up arms again. It may have been a condition for their acceptance into the Church of God, that they publicly confess and covenant to never fight again.
What may have unintentionally happened here is that an additional "step" towards salvation was added for those who were not Nephites, or who had previously apostatized from the church. For non-Nephites and perhaps for excessive sinners the church, or at least some of the church leaders, may have been requiring that certain people go through a public confession of their sins and make an additional covenant that was not required of Nephites. It may not have been a problem when the people of Ammon did it for the first time, but the practice may have continued and approximately 100 years later the practice had become established among some branches of the church.
Thus when the church met for their general conference at the temple in the land Bountiful, they were discussing what was required of new members to join the Church of God. Some Nephites may have insisted that baptism was not necessary since the Law of Moses was fulfilled. Others may have disputed the manner of baptism, and there may have been still others who insisted that all new members, or at least former Lamanites/Gadianton Robbers needed to perform the public confession and covenant making before the altar of God. This debate was causing significant contention in the church and it was apparently the primary reason why Christ came to visit them.
After settling the immediate dispute regarding baptism, and any other additional requirements, Jesus then proceeded to give them the new law and new covenant, just as he had done in Israel, the law that would replace the Law of Moses. While much of what I have presented is speculation, we can get a sense that the history, culture and societal issues confronted by the Nephites were a bit more complex than Mormon could have expressed given his size constraints. But we can get hints of the more complex issues dealt with by the Nephites if we are willing to read the Book of Mormon more closely and to consider arguments that we have never considered before.