It is most curious that the only place in the New Testament where there is reference to vicarious work for the dead is in Corinthians. “If in this life only we have hope in Christ we are of all men most miserable.” (Cor 15:19) The statement makes reference to another life besides this one, where people obviously have hope in Christ’s atonement and in eternal life. The 22nd verse refers to the fact that through Adam all men die and in Christ shall all be made alive.
At the funeral of Simon Brunson, in 1840, the Prophet Joseph Smith quoted Paul speaking to the Corinthians, as quoted above, and said that, Paul was talking to a people who understood baptism for the dead, for it was practiced among them.” There was a widow, at that funeral, whom had lost a son. The son had not been baptized, and the Prophet assured her that the Plan of Salvation was calculated to save all who were willing to obey the requirements of the law of God, giving much hope to the widow, I’m sure.
Shortly after that sermon by the Prophet, the Mississippi River around Nauvoo became a place where baptisms for the dead were common from 1840 until 1845. All the families who have lived on the earth and will yet live on the earth will be blessed with the same opportunity, because that’s the Plan put forth by the Father for His children, and who can stay His hand? Those who profess otherwise do not understand the Father’s love and mercy. All will be resurrected from the dead but that is not the same as being ushered into the Father’s presence. Christ stated in John what the minimum requirements for that were “Verily, verily I say unto thee, Except a man be born of water and of the spirit he cannot enter into the kingdom of God. ( John 3:5) The book of Moses in the Pearl of Great Price says it a little differently (Moses 6:59), “That by reason of transgression cometh the fall, which fall bringeth death, and in as much as ye were born into the world by water, and blood, and the spirit, which I have made, and so became of dust a living soul, even so ye must be born again into the kingdom of heaven, of water, and of the spirit, and be cleansed by blood even the blood of mine only Begotten; that ye might be sanctified from all sin, and enjoy the words of eternal life…” and in verse 62, “And now behold, I say unto you: This is the Plan of Salvation unto all men, through the blood of mine Only Begotten…”
So how are those who have died without an opportunity to hear of the Plan, to have justice, to have equal opportunity for Salvation through Christ’s atoning sacrifice? The only way is to have their earthly ordinance performed by someone yet living. Going back to Corinthians “Else what shall they do which are baptized for the dead, if the dead rise not at all? Why are they then baptized for the dead?” (Corinthians 15:29) The key is through vicarious administrations of those ordinances. Vicarious meaning a living person stepping in and doing the ordinances for one who is dead. This is the great work being done in these latter days by members of The Church of Jesus Christ of Latter-day Saints.