Where we are
Moroni 3 is four verses preserving the manner of ordination — how the Nephite disciples, called the elders of the church (v. 1), ordained priests and teachers. Like the chapters around it, it is brief and practical, part of the cluster of ordinance chapters with which Moroni closes the record. Having preserved the gift of the Holy Ghost (Moroni 2), he now preserves the conferral of priesthood office, so that a future church would know the exact pattern: prayer to the Father in the name of Christ, the laying on of hands, and a plain ordaining formula naming the office and its purpose. The chapter is a small but essential piece of the practical inheritance Moroni leaves — the manner of calling and setting apart the men who would preach and serve.
The chapter's four verses give the whole pattern: the elders ordained priests and teachers (v. 1); after praying to the Father in Christ's name, they laid on hands (v. 2); they spoke the ordaining words — In the name of Jesus Christ I ordain you to be a priest... to preach repentance and remission of sins through Jesus Christ, by the endurance of faith on his name to the end (v. 3); and they ordained according to the gifts and callings of God unto men... by the power of the Holy Ghost (v. 4).
The verses that carry the chapter are these. Verse 3 holds the ordaining formula and its purpose — to preach repentance and remission of sins through Jesus Christ, by the endurance of faith on his name to the end. And verse 4 names the authority and the principle — ordained according to the gifts and callings of God unto men... by the power of the Holy Ghost. The chapter exists to preserve the manner of ordination, grounding every priesthood calling in the name of Christ, the gifts of God, and the power of the Holy Ghost.
The manner of ordination (verses 1–4)
In the name of Jesus Christ I ordain you to be a priest... to preach repentance and remission of sins through Jesus Christ, by the endurance of faith on his name to the end. Amen. — Moroni 3:3
The ordaining formula is brief, exact, and full of doctrine. It is done in the name of Jesus Christ — the same authority that governs the gift of the Holy Ghost (Moroni 2) and the sacrament prayers (Moroni 4–5); every ordinance is in Christ's name. And the office is defined by its purpose: to preach repentance and remission of sins through Jesus Christ. The priest is not ordained to status or power but to a work — the preaching of repentance and the remission of sins, the same work that has run through the whole Book of Mormon. And the formula names the condition of that work's success: by the endurance of faith on his name to the end. The office is held, and the preaching made effective, only by enduring faith. The ordination thus binds the one ordained to the same standard he will preach — faith on Christ's name, endured to the end. The brevity of the formula is its strength: no elaboration, no ceremony beyond the essential, just the name of Christ, the office, the purpose, and the condition.
And after this manner did they ordain priests and teachers, according to the gifts and callings of God unto men; and they ordained them by the power of the Holy Ghost, which was in them. — Moroni 3:4
The closing verse names two things that guard the ordinance from becoming mere human appointment. First, men are ordained according to the gifts and callings of God unto men — not by ambition, not by lineage, not by popularity (the priestcraft of Nehor, Alma 1), but according to the gifts God has given and the callings God has issued. The calling originates with God; the ordination ratifies it. Second, they are ordained by the power of the Holy Ghost, which was in them — the ordaining elders act not by their own authority but by the Spirit's power within them. Both clauses locate the ordinance entirely in God: God calls, God gives the gifts, and the Holy Ghost empowers the ordination. This is the precise opposite of priestcraft, in which men set themselves up for gain. Here the office is God's to give, conferred by his Spirit, for the work of preaching Christ. Moroni preserves the pattern so that the future church would ordain as the disciples did — by the Spirit, according to God's callings, in the name of Christ.
How the chapter is built
Moroni 3 is built as a companion to Moroni 2, and the two ordinance chapters share a structure: occasion, the prayer-then-laying-on-of-hands pattern, the exact words, and the result by the power of the Holy Ghost. The architecture is deliberately parallel, so that the reader sees the consistent form of all the ordinances — every one begins with prayer to the Father in Christ's name, proceeds by the laying on of hands, and is effected by the Spirit. The brevity is faithfulness: Moroni preserves the pattern exactly, without elaboration, so the future church could ordain as the disciples did.
The chapter is also built to guard against priestcraft, the recurring corruption the Book of Mormon has exposed from Nehor (Alma 1) to the latter-day churches Moroni saw (Mormon 8:32–33). It does this by grounding ordination entirely in God: the gifts and callings of God unto men, and the power of the Holy Ghost (v. 4). The architecture locates the source of the office outside the man ordained — God calls, God gifts, the Spirit empowers — so that no one can claim the office for himself or use it for gain. The chapter's careful attribution of the whole ordinance to God is the structural answer to priestcraft: the office is not a possession to be seized but a calling to be received, conferred by the Spirit, in the name of Christ, for the work of preaching repentance.