Those of us who have been bitten by the family history bug know how fun it can be. But this isn’t why we have the largest genealogical library in the world and why 13 million Mormons are encouraged to research their family roots. Rather, we are driven by our doctrine that teaches that marriage and families can continue beyond this life. But this can only happen when families are sealed together in one of the Lord’s holy temples around the world and united for all eternity.
That’s fine for all of us today who have the chance to be sealed in a temple, but what about our ancestors who die without the opportunity to receive ordinances like baptism, or the blessings of being an eternal family? Does it make sense that God would simply say, "Too bad, tough luck?" Of course it doesn’t. When Christ organized His Church anciently, it included vicarious work for the dead and the practice of performing ordinances for deceased relatives "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?" (1 Corinthians 15:29). Christ’s restoration of his original Church to the earth through the Prophet Joseph Smith included the ancient practice of performing these ordinances for our deceased relatives in holy temples. The gospel of Jesus Christ includes the same blessings today in holy temples.
Genealogical or family history research is the essential forerunner of temple work for our deceased ancestors. We do it to obtain names and other genealogical information so these temple ordinances can be performed for our kindred dead. Our ancestors then are taught the gospel in the spirit world and have the choice to accept or reject the work performed for them. Mother Teresa once said that "loneliness and the feeling of being unwanted is the most terrible poverty." The thought that this poverty of loneliness—this being unwanted and separated from loved ones—could extend beyond this life is truly sad and something temple work can prevent.