Amulek noted: “After this day of life, which is given us to prepare for eternity, behold, if we do not improve our time while in this life, then cometh the night of darkness wherein there can be no labor performed.” (Alma 34:33; see also 3 Nephi 27:33) According to Rodney Turner, this statement is sometimes misinterpreted. The “night of darkness” is not death, but resurrection. (See Alma 41:5) The “day of this life” or, in other words, the “probationary state” or “preparatory state” in which we prepare for eternity (Alma 42:10) includes the postmortal sojourn in the spirit world. Were this not the case, there would be no purpose in preaching the gospel to the dead or in performing ordinances for them. Unlike water baptism, faith and repentance cannot be “performed” vicariously; only the immortal spirit can exercise faith unto salvation. Eternal life depends upon eternal obedience.
Latter-day Saints commonly equate eternal life with exaltation in the celestial kingdom. However, the concept of multiple heavens or conditions of salvation, as revealed to Joseph Smith in Doctrine and Covenants 76, is not found in the Book of Mormon. Instead, it speaks in terms of absolutes; one is either saved in the presence of God or damned with the devil and his angels. (See Mosiah 16:10-11) Consequently, in the Book of Mormon, eternal life is in opposition to eternal death. (See 1 Nephi 14:7; 2 Nephi 1:13; 2:27-29; 10:23). However, eternal life is actually subdivided into “many mansions” or degrees of glory. This being the case, eternal life is tantamount to salvation as such. That is, every soul resurrected into any state of immortal glory enjoys a degree of eternal life. (See D&C 29:26-29, 88:21-24.) A fullness of eternal life is exaltation and the “continuation of the lives” (D&C 132:22). Any state of salvation less than this is a state of damnation or death insofar as spirit progeny or dominion is concerned. (See D&C 131:1-4; 132:25). [Rodney Turner, “Two Prophets: Abinadi and Alma,” in Studies in Scripture: Book of Mormon, Part 1, p. 252]