Latter-day Saints identify the performance of proxy temple ordinances-water baptism, endowments, and family sealings- as temple work. This is how Dr. Robert Millet describes LDS temple work:
Because the sacraments or ordinances of the Church are earthly ordinances and must be performed on this side of the veil of death, Latter-day Saints go into temples to receive the sacraments in behalf of those who have died without them.
The Encyclopedia of Mormonism explains the nature of the LDS temple ordinances for the dead this way:
Temple ordinances are not mere signs. They are channels of the Spirit that enable one to be born of God in the fullest sense and to receive all the covenants and blessings of Jesus Christ. The performing of earthly ordinances by proxy for those who have died is as efficacious and vitalizing as if the deceased person had done them. That person, in turn, is free to accept or reject the ordinances in the spirit-world.
The LDS Church makes it clear to its members that many Mormon converts and family members are continuing to abide in spirit-prison as they wait to receive proxy temple ordinances on their behalf. As a result, individual Mormons experience a tremendous amount of pressure by LDS Church officials to dedicate a significant amount of time and effort in performing their temple duties for the dead:
Some of us have had occasion to wait for someone or something for a minute, an hour, a day, a week, or even a year. Can you imagine how our progenitors must feel, some of whom have perhaps been waiting for decades and even centuries for the temple work to be done for them.
LDS officials exhort individual Mormons to visit the temple to perform rituals for the dead regularly. Since I serve as a pastor in a church located only a block from the Arizona temple in the city of Mesa, almost every day I drive by a parking lot full of cars left behind by Mormons performing ritual ordinances for the dead inside the temple as their act of obedience. Many Mormons testify that the veil between the living and the dead becomes very thin in the temple. Interestingly, some Mormons say that while performing temple ordinances for the dead, they often feel the presence of the dead person in question.
Mormon Family Genealogical Research
Mormonism teaches that the salvation temple ordinances on behalf of the dead can be performed only once a dead person can be officially identified and specifically named. This official identification process is the primary purpose behind the extensive genealogical research emphasis in the LDS Church. As one Mormon writer clarifies:
Church members are making every effort to identify every man, woman and child who ever lived on the face of the earth so that baptisms and other ordinances can be performed on their behalf. Until the Millennium, we are seeking out the dead, one name at a time.
Although many people today develop their genealogies as a hobby or out of a general interest in their past heritage, faithful Mormons instead engage in a rigorous genealogical research routine in order to submit names to the temple so that ordinances for the dead can be officially completed and recorded.
Mormon Temple Baptisms for the Dead
Joseph Smith initiated and strongly promoted water baptism for the dead among the Latter-day Saints:
If we can baptize a man in the name of the Father and the Son and of the Holy Ghost for the remission of sins it is just as much our privilege to act as an agent and be baptized for the remission of sins for and in behalf of our dead kindred who have not heard the gospel or fullness of it.
Smith first taught the doctrine of the baptism for the dead at a Latter-day Saints funeral in the city of Nauvoo, Illinois, on August 10, 1840, approximately ten years after the LDS Church had been started in New York. The LDS Doctrine and Covenants Student Manual reads:
As early as August 10, 1840, in a powerful address at the funeral of Seymour Brunson, the Prophet introduced the doctrine of baptism for the dead to a startled congregation of Saints.
The first proxy water baptisms for the dead by Latter-day Saints were performed in the Mississippi River, and the first baptisms for the dead in the unfinished Nauvoo temple were initiated on November 21, 1841.
In the early years of the LDS Church, water baptisms were performed only for direct ancestors, usually going back approximately four generations or so. Today, however, Latter-day Saints perform water baptisms for the dead not only for their eceased family members but also for any other person who has been officially identified through the LDS name-extraction program. Witnesses are required for baptisms of the dead, official records must be kept, and women are baptized for women and men are baptized for men.
The Latter-day Saints support their doctrine of proxy water baptism for the dead on a single Bible verse: What do people mean by being baptized on behalf of the dead? If the dead are not raised at all, why are people baptized on their behalf? (1 Cor. 15:29).
In the overall context of this passage, however, Paul is not supporting, and certainly not commanding, the practice of water baptism for the dead. He simply argues that since a few in the city of Corinth were practicing it, then they must believe in the resurrection of the dead, which some in Corinth were denying (see 1 Cor. 15:12).
One of the most convincing arguments against Mormonism's practice of water baptism for the dead is that there is absolutely no biblical evidence that the apostle Paul or any other New Testament leader ever engaged in or encouraged the practice himself. Total biblical silence concerning a so-called key salvation practice does not bode well for those that believe and propagate it.
Salvation for the Dead during the Mormon Millennium
Some major problems face Mormonism's teaching and practice of water baptism for the dead: multitudes of genealogical records have been lost or destroyed over the centuries; there are simply not enough Mormons and temples to perform the required ordinances for the dead; and billions upon billions of people have lived since the world began, and to perform proxy temple ordinances for all of them is simply a logistical impossibility.
How do Mormons respond to these obvious problems? Many Latter-day Saints find their answers in the future Mormon millennium. In the millennium, everything that is impossible today will be solved, as emphasized by Bruce McConkie: Obviously, due to the frailties, incapacities, and errors of mortal men, and because the records of past ages are often scanty and inaccurate, this great work cannot be completed for every worthy soul without assistance from on high. The millennial era is the time, primarily, when this assistance will be given by resurrected beings. Genealogical records unknown to us will then become available. Errors committed by us in sealings or other ordinances will be rectified, and all things will be arranged in proper order. Temple work will be the great work of the millennium.
Mormonism seems to satisfy its internal doctrinal and practice challenges related to salvation for the dead by appealing to the fact that it will all work out somehow during the millennium- a rather convenient solution.
The Mormon Millennium
The Latter-day Saints' tenth Articles of Faith creedal statement reads, "We believe in the literal gathering of Israel and in the restoration of the Ten Tribes; that Zion (the New Jerusalem) will be built upon the American continent; that Christ will reign personally upon the earth; and, that the earth will be renewed and receive its paradisiacal glory."
According to Mormonism, following the second coming of Jesus Christ, he will rule on the earth for a millennium, or a period of a thousand years. At the beginning of the millennium, the entire earth will be transformed into the paradisiacal condition that initially prevailed in the garden of Eden, at which time its inhabitants will speak the pure language spoken by Adam. Satan will be bound, and there will be a new heaven and a new earth.
The millennium will be a time of righteousness and peace on the earth, and it will have two capital cities-Old Jerusalem in Palestine and New Jerusalem (Zion) in America's state of Missouri.
The New Mormon World
Again, according to Mormonism, at the end of the millennium, Satan will be loosed and the great last battle of Gog and Magog will occur. Led by Adam-the archangel Michael in preexistence-the hosts of heaven will defeat the armies of Satan. After the resurrection of those still dwelling in the Telestial kingdom, everyone will experience God's final judgment and be sent to his or her eternal destination in the Celestial, Terrestrial, or Telestial kingdom or eternal hell. In the end, the entire earth will be totally cleansed and become the new Celestial world inhabited exclusively by true and faithful Mormons forever.