The Lord’s covenant with Alma promising eternal life is known as the more sure word of prophecy or having his calling and election made sure. On May 17th, 1843, The Prophet Joseph Smith instructed: “The more sure word of prophecy means a man’s knowing that he is sealed up unto eternal life, by revelation and the spirit of prophecy, through the power of the Holy Priesthood. It is impossible for a man to be saved in ignorance” D&C 131:5–6). Peter admonished the New Testament Saints to make their calling and election sure. “But he that lacketh these things is blind, and cannot see afar off, and hath forgotten that he was purged from his old sins. Wherefore the rather, brethren, give diligence to make your calling and election sure: for if ye do these things, ye shall never fall” (2 Peter 1:10–11).
To have one’s calling and election made sure is to receive the second Comforter. The Prophet Joseph Smith explained:
The Doctrine of Election. St. Paul exhorts us to make our calling and election sure. This is the sealing power spoken of by Paul in other places.
“13 In whom ye also trusted, that after ye heard the word of truth, the Gospel of your salvation: in whom also after that ye believed, ye were sealed with that Holy Spirit of promise,
“14 Which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of His glory, that we may be sealed up unto the day of redemption.” — Ephesians, 1 chapter.
This principle ought (in its proper place) to be taught, for God hath not revealed to Joseph, but what he will make known to the Twelve, and even the least Saint may know all things as fast as he is able to bear them, for the day must come when no man need say to his neighbor, Know ye the Lord; for all shall know Him (who remain from the least to the greatest. How is this to be done? It is to be done by this sealing power, and the other Comforter spoken of, which will be manifest by revelation. [TPJS, 149]
Being assured of eternal life does not end one’s service and responsibilities in the kingdom or the Church. In fact it will increase them. Alma is instructed to serve the Lord by gathering his sheep (Mosiah 26:20). This assignment is also one of the missions of the Church: to “proclaim the gospel of Jesus Christ.” Those who receive the word of God will be received into the church (vv. 21–22). They will have been prepared to receive some of the ordinances necessary for exaltation, another mission of the church, and will be prepared to receive further ordinances. Having become a part of Christ’s family by taking his name upon them, they will come to know him and have a place eternally at his right hand (vv. 23–24).