The “rest of God” does not describe a condition of inactivity, idleness, and perpetual sleep. Rather, it connotes the rest received from wickedness, pain, and the tribulations of the world. It is similar to the state of translated beings who were not to suffer pain nor sorrow save it were for the sins of the world (3 Nephi 28:38). The term, “the rest of God,” is further described below:
"’Now this Moses plainly taught to the children of Israel in the wilderness, and sought diligently to sanctify his people that they might behold the face of God;
But they hardened their hearts and could not endure his presence; therefore, the Lord in his wrath, for his anger was kindled against them, swore that they should not enter into his rest while in the wilderness, which rest is the fulness of his glory.’ (D&C 84:23–24)
"These verses indicate a connection between seeing the face of God, having the power of the priesthood, having the key of the knowledge of God, and entering into the rest of God.
"Alma also understood that entering into the rest of God meant seeing the face of God and experiencing his fulness, and that this could only be accomplished through the power of the higher priesthood. In the broader context within which Alma’s sermon on priesthood appears, Alma referred to rest four times before the sermon (in Alma 12:34–37) and four times in the concluding portions of the sermon (Alma 13:12, 13, 16, and 29). Alma consciously emphasized the word ’rest,’ repeating it again and again to accentuate the importance of the concept.
"In a sense, the word rest is an idiom in that its meaning is broader than the word implies. Rest doesn’t just refer to lying in bed or doing no work. Rest is possible only through the atonement of Christ and is earned through faith, repentance, and not hardening our hearts (Alma 12:37)…the prophet Enos bids farewell to his people and expresses his assurance of eternal life.
’And I soon go to the place of my rest, which is with my Redeemer; for I know that in him I shall rest. And I rejoice in the day when my mortal shall put on immortality, and shall stand before him; then shall I see his face with pleasure, and he will say unto me: Come unto me, ye blessed, there is a place prepared for you in the mansions of my Father. Amen.’ (Enos 1:27)
“These scriptural passages afford the hope and comfort that all the faithful saints who have been valiant in the service of God and who have kept his commandments and loved their fellow beings may confidently look forward to the rest of God.” (FARMS: Journal of Book of Mormon Studies, Spring 1996, vol. 5, no. 1, p. 116-8)
Alma 13:1 the Lord God ordained priests, after his holy order, which was after the order of his Son
Bruce R. McConkie
“Book of Mormon prophets gave the title priest to officers known in this dispensation as high priests. That is, they were priests of the Melchizedek Priesthood, or as Alma expressed it, ’the Lord God ordained priests, after his holy order, which was after the order of his Son.’ (Alma 13:1-20.) Since there was no Aaronic Priesthood among the Nephites in Alma’s day (there being none of the lineage empowered in pre-meridian times to hold that priesthood), there was no need to distinguish between priests of the lesser and greater priesthoods.” (Mormon Doctrine, p. 599)