The first account of Nephites practicing baptism is at the Waters of Mormon, where Alma baptized himself and his followers. Alma had fled from the Lehi-Nephi group founded by Zeniff and later led by Noah and then Limhi. This group had broken off from the main Nephite-Mulekite group in Zarahemla c. 200 BC, and the two groups had no contact until c. 120 BC, when both Alma's group and the main Lehi-Nephi group under Limhi went to Zarahemla and united with the main Nephite-Mulekite group ruled by Mosiah II.
It was during this 80-year separation that the both the baptisms at the Waters of Mormon (c. 147 BC) and King Benjamin's address at Zarahemla (c. 124 BC) occurred.
The estimated dates I'm using are those provided by the CJCLDS in their current edition of the Book. I'm not vouching for their accuracy; I include them only to establish the sequence of events. Here's a simple diagram of that sequence, without dates and not to scale:
For convenience, I will refer to the groups that came together under Mosiah II as the Nephites (the main Zarahemla group, a mixture of Nephites proper and Mulekites), the Zeniffites, and the Almaites.
With this background in mind, we return to Alma at the Waters of Mormon. When Alma performed his first baptism, he also baptized himself (Mosiah 18:14-15), which implies that he had not been baptized before. Alma was a Zeniffite priest, and if priests were not baptized it seems unlikely that anyone was. Another possibility is that Alma had been baptized but no longer considered a baptism performed by the corrupt priests of Noah to be valid and therefore had to do it again. Against this we have the fact that Alma claims to baptize "having authority from the Almighty God" (Mosiah 18:13), and it would seem that this declaration of authority could only refer to his status as an ordained Zeniffite priest. He apparently considered Zeniffite priests to have legitimate authority to perform religious ceremonies, even though their teachings and practices had become corrupt. From all this we conclude that the Zeniffites almost certainly did not practice baptism. Alma was either innovating or else restoring an earlier Nephite practice which the Zeniffites had abandoned.
While Joseph Smith would later make it an article of the Mormon faith that baptism is "for the remission of sins" (A of F 4), Alma says nothing about that. His baptism had two functions. First, it marked a covenant with God to "serve him and keep his commandments" (Mosiah 18:10) "until you are dead as to the mortal body" (Mosiah 18:13). Second, baptism was a way to "come into the fold of God, and to be called his people" (Mosiah 18:8), and those who were baptized "were called the church of God, or the church of Christ, from that time forward. And it came to pass that whosoever was baptized by the power and authority of God was added to his church" (Mosiah 18:17).
Some decades later, King Benjamin in Zarahemla, with no knowledge of Alma or the Zeniffite group from which he had come, would do with his people something very similar to what Alma had done at the Waters of Mormon. After listening to Benjamin's address, his subjects say that they
are willing to enter into a covenant with our God to do his will, and to be obedient to his commandments in all things that he shall command us, all the remainder of our days (Mosiah 5:5)
This is the same covenant that was made by baptism at the Waters of Mormon -- to obey God's commandments until death. If Alma's baptism was an existing Nephite practice and not an innovation, we would expect that Benjamin would at this point instruct his subjects to be baptized. Instead, he says
Ye have spoken the words that I desired; and the covenant which ye have made is a righteous covenant. And now, because of the covenant which ye have made ye shall be called the children of Christ (Mosiah 5:6-7)
He twice speaks of "the covenant which ye have made." To publicly announce their willingness to make the covenant is to make the covenant. No further ceremony is required. The covenant was made by a large crowd of people as they were gathered to hear Benjamin speak. If they had all been baptized then and there, it would have been a major event and have taken quite some time. From the fact that no such action is mentioned, we can be pretty confident that it didn't happen. Just as those who make Alma's baptismal covenant are thenceforth "called the church of God, or the church of Christ," those who make Benjamin's non-baptismal but otherwise identical covenant are thereafter "called the children of Christ."
Benjamin's people made exactly the same covenant as Alma's, and with the same result. If baptism were the established way of making such covenants among the Nephites, the story of Benjamin's people would include baptism, but it doesn't. We therefore conclude that baptism was introduced by Alma, and that the Nephites did not practice it before.
In around 120 BC -- approximately four years after Benjamin's people had made their covenant -- the Zeniffites (under King Limhi) and the Almaites both come to Zarahemla and join the main Nephite body under Benjamin's successor, Mosiah II. The Almaites have all been baptized, made the associated covenant, and become known as the "church of Christ." In the main Nephite body, "there was not one soul, except it were little children, but who had entered into the covenant and had taken upon them the name of Christ" (Mosiah 6:2), though they had done so under Benjamin and without the rite of baptism. As for the Zeniffites, we are quite confident that they were not baptized, and there is no record of their having made any equivalent covenant.
After this union of the three groups, Mosiah "caused that all the people should be gathered together" (Mosiah 25:1), and Alma addressed them all. "And Alma did speak unto them, when they were assembled together in large bodies, and he went from one body to another, preaching unto the people repentance and faith on the Lord" (Mosiah 25:15). The Zeniffites (Limhi's people) responded to this preaching by being baptized:
And it came to pass that after Alma had taught the people many things, and had made an end of speaking to them, that king Limhi was desirous that he might be baptized; and all his people were desirous that they might be baptized also. Therefore, Alma did go forth into the water and did baptize them; yea, he did baptize them after the manner he did his brethren in the waters of Mormon; yea, and as many as he did baptize did belong to the church of God; and this because of their belief on the words of Alma.And it came to pass that king Mosiah granted unto Alma that he might establish churches throughout all the land of Zarahemla; and gave him power to ordain priests and teachers over every church (Mosiah 25:17-19).
Only the Zeniffites are baptized at this point. There is no record of any of the Zarahemla Nephites wanting to be baptized after hearing Alma preach. From the language of v. 19, we might conclude that Alma's movement remained a minority sect and that most of the Nephites did not join, though Mosiah tolerantly "granted unto Alma that he might establish churches."
However, we are told that during the reign of Mosiah, those who did not belong to Alma's church "were not half so numerous as the people of God" (Mosiah 26:5). We don't know how big the Zeniffite group was, but they can scarcely have had twice the population of the main Nephite body, so we must assume that most of the Zarahemla Nephites did join Alma's movement. The most logical conclusion is that, since the purpose of baptism is to covenant lifelong obedience to God and to become his people, and since the Nephites had already done that, there was no need for them to do it again by being baptized. They had in effect made the baptismal covenant, but had done so before baptism became established among them as the way to make such covenants, and they were therefore "grandfathered in."
This is confirmed by the nature of the group that did not belong to the church.
Now it came to pass that there were many of the rising generation that could not understand the words of king Benjamin, being little children at the time he spake unto his people; and they did not believe the tradition of their fathers. . . . And they would not be baptized; neither would they join the church (Mosiah 26:1, 4).
It was explicitly stated that all of King Benjamin's subjects except "little children" entered into his baptism-equivalent covenant. It was only among this "rising generation" that some refused to be baptized because they were the only Nephites who were expected to be baptized. Those who had been of age in Benjamin's time had already done something that was counted as being in effect baptism and were not expected to do it again.
I will have more to say in a later post about the rising generation's specific reasons for not wanting to be baptized. Here I just cite their refusal as evidence that baptism was only expected of those who had not covenanted under Benjamin.
I think I've made a pretty strong case that Alma and Benjamin independently introduced the idea of making a covenant and becoming the people of Christ, that only Alma's version of this covenant involved baptism, and that baptism was not practiced by the Nephites before Alma brought it to them.
