In Malachi 4:5 we read, "5 ¶ Behold, I will send you Elijah the prophet before the coming of the great and dreadful day of the Lord:" This prophesy of Malachi's return has been long awaited by the Jews. Even today, they set a chair for Elijah at their passover. But why would Elijah return? What was his mission? We can go on to read the next verse. "6 And he shall turn the heart of the fathers to the children, and the heart of the children to their fathers, lest I come and smite the earth with a curse."
After Joseph Smith's first vision, some time went by without any further instruction from heaven. He wondered if his own weaknesses had made him unworthy of divine communication. He recorded: "after I had retired to my bed for the night, I betook myself to prayer and supplication to Almighty God for forgiveness of all my sins and follies, and also for a manifestation to me, that I might know of my state and standing before him; for I had full confidence in obtaining a divine manifestation, as I previously had one." (JSH 1:29) In response to this prayer, he was visited by the angel Moroni, who was a messenger from God. Moroni explained to Joseph that there was a record hidden in a nearby hill. Joseph recorded, "He said there was a book deposited, written upon gold plates, giving an account of the former inhabitants of this continent, and the source from whence they sprang. He also said that the fulness of the everlasting Gospel was contained in it, as delivered by the Savior to the ancient inhabitants;" (JSH 1:34) Then Moroni began to quote the scripture from Malachi 4:5 that I quoted above. But then he went on to quote the next verse slightly different. He said, "And he shall plant in the hearts of the children the promises made to the fathers, and the hearts of the children shall turn to their fathers. If it were not so, the whole earth would be utterly wasted at his coming." JSH 1:39
What was the promise made to the fathers? What was so important that would cause the utter waste of the Earth if it didn't come to pass? President Joseph Fielding Smith taught: "What was the promise made to the fathers that was to be fulfilled in the latter days by the turning of the hearts of the children to their fathers? It was the promise of the Lord made through Enoch, Isaiah, and the prophets, to the nations of the earth, that the time should come when the dead should be redeemed" (Doctrines of Salvation, comp. Bruce R. McConkie, 3 vols. [1954–56], 2:154).
The plan of salvation was developed by God to provide salvation for all men. The Savior's atonement was the most crucial element in this plan. The plan called for ordinances such as baptism. Jesus, himself taught, "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) A merciful Heavnely Father provided in the plan a way for those who died without the gospel to receive the ordinance of baptism. In the temple, we can be baptized for our ancestors who died without an opportunity to do this work for themselves.
In addition to the ordinance of baptism, the ordinance of "sealing" of couples and families as an eternal unit is also performed in the temple. The "sealing" of families is one of the important purposes of the creation of this Earth. Without these redeeming ordinances, our dead could not be saved.
The Priesthood keys of this ordinance were held by the prophet Elijah. On April 3, 1836, Elijah the prophet did return to the Earth. His purpose in coming was to bestow the "sealing keys" of the Priesthood upon the prophet Joseph Smith. When he came to him, he said, "14 Behold, the time has fully come, which was spoken of by the mouth of Malachi—testifying that he [Elijah] should be sent, before the great and dreadful day of the Lord come—
15 To turn the hearts of the fathers to the children, and the children to the fathers, lest the whole earth be smitten with a curse—
16 Therefore, the keys of this dispensation are committed into your hands; and by this ye may know that the great and dreadful day of the Lord is near, even at the doors." (Doctrine and Covenants 110:13-16)
Those keys have been bestowed upon every living prophet since Joseph Smith, and are still used today to perform eternal marriages, and the sealing of families as an eternal unit.
While there are those who still await Elijah's return, we in the Church of Jesus Christ of Latter-day Saints testify that he has already returned, and that he brought the Priesthood keys necessary for the salvation of the dead. We do our geneology, and in so doing, we turn our hearts to our fathers. By doing vicarious baptism for our dead, we are fulfilling the promise made to our forefathers by God, that a way would be provided for the dead to be redeemed. I am thankful that the ordinances of the gospel are available to not only the living, but also to the dead.