Yahweh assures Alma2, “Marvel not that all mankind, yea, men and women… must be born again.” Alma2’s terminology is familiar to us, but the language fits Book of Mormon doctrine of the time more closely than contemporary LDS theology.
First, modern Saints typically equate with “being born of the spirit” with baptism and the gift of the Holy Ghost, but neither of these events is part of Alma2’s experience (although he may have received these ordinances earlier). Rather, his particular “birth” is redemption from sin. (See Alma 36:12–21 for the details of his sin/redemption contrast.) Alma2 is born of the Spirit because the atonement of Jesus Christ was applied to his soul (not because of the gift of the Holy Ghost as in modern terminology). It constituted a new birth in that his soul became freed from the bonds of sin—innocent like a newborn child.
This context applies to King Benjamin’s admonition: “And now, because of the covenant which ye have made ye shall be called the children of Christ, his sons, and his daughters; for behold, this day he hath spiritually begotten you; for ye say that your hearts are changed through faith on his name; therefore, ye are born of him and have become his sons and his daughters” (Mosiah 5:7).
Benjamin, significantly, also describes this process as being “spiritually begotten.” Mormon began this particular discussion of Alma2 with a direct reference to the Benjaminic covenant: “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” (Mosiah 26:1).
Alma2, by accepting the atonement, makes the covenant that he has previously rejected, a point stressed by Mormon, who structured the text so that Benjamin’s covenant frames Alma2’s “birth.”