When the Savior came to the Nephites, he established the Church in its fulness among them, and he informed them that former things had passed away, for they were all fulfilled in him. He gave the Nephites all the authority of the priesthood which we exercise today. Therefore we are justified in the belief that not only was the fulness of the Melchizedek Priesthood conferred, but also the Aaronic, just as we have it in the Church today; and this Aaronic Priesthood remained with them from this time until, through wickedness, all priesthood ceased. We may be assured that in the days of Moroni the Nephites did ordain teachers and priests in the Aaronic Priesthood; but before the visit of the Savior they officiated in the Melchizedek Priesthood. (Answers to Gospel Questions 1:124, 126.)
“After This Manner Did They Ordain Priests and Teachers”
in earlier Nephite times priests and teachers were called and ordained to service in the kingdom. These priests and teachers were not officers in the Aaronic Priesthood as we know it today.
They were priests and teachers in the general sense that they were Melchizedek Priesthood servants who ministered to the people and taught the gospel (see 2 Nephi 5:26; Jacob 1:18; Mosiah 18:18; see also Commentary 1:225; 2:260).
It is not explicit in Moroni’s account whether he is referring to “priests and teachers” in a generic way, meaning those who would minister under the Melchizedek Priesthood, or to the literal offices of priest and teacher in the Aaronic Priesthood.
President Joseph Fielding Smith explained: “There were no Levites who accompanied Lehi to the Western Hemisphere. Under these conditions the Nephites officiated by virtue of the Melchizedek Priesthood from the days of Lehi to the days of the appearance of our Savior among them.
It is true that Nephi ’consecrated Jacob and Joseph’ that they should be priests and teachers over the land of the Nephites, but the fact that the plural terms priests and teachers were used indicates that this was not a reference to the definite office in the priesthood in either case, but it was a general assignment to teach, direct, and admonish the people. Otherwise the terms priest and teacher would have been given, in the singular … .”