In response to a question asked today:
The Church of Jesus Christ of Latter-day Saints is a temporary institution which will cease to exist after this life. There is no vision, revelation, scripture or statement promising us that the church as an institution will continue to exist after mortality. What the scriptures, visions, and revelations do tell us about the eternal description of the saved is that it is “the Church of the Firstborn” or “the Church of the Lamb.” Membership in that group is separate from membership in The Church of Jesus Christ of Latter-day Saints.
Nephi uses “Church of the Lamb” (see e.g., 1 Ne. 14: 12) to describe the latter-days group over whom the Lord will watch. Interestingly, although Joseph had this revelation before him when he organized the church, he did not choose the “Church of the Lamb” as the organization’s name.
When modern revelation refers to those who inherit the Celestial Glory, it calls them members of the “Church of the Firstborn” (see, e.g., D&C 76: 67 also 93: 22). Those who are chosen in our day to belong to the Church of the Firstborn are shown only one way in which that takes place. In a revelation given to Joseph Smith while translating the New Testament, Section 77, Joseph gave this explanation of the latter-day 144,000 saved persons in verse 11: “they are they who are ordained out of every nation, kindred, tongue, and people, by the angels to whom is given power over the nations of the earth, to bring as many as will come to the church of the Firstborn.”
At the time Joseph received the explanation recorded in Section 77 (March 1832) the church had existed for over two years. When the official name was given in 1838 (D&C 115: 4) the name chosen for the earthly, temporary organization was The Church of Jesus Christ of Latter-day Saints – not the Church of the Firstborn.
The Church of the Firstborn exists on the “other side” so to speak. You qualify to get there by how you live here. But you have to be invited into that church by the “angels to whom is given power” to extend that invitation.
Joseph Smith didn’t “choose” the name of the Church when he organized it…Jesus did (D&C 115:4).