"Religion 261, Introduction to Family History, is a one-semester course in which you will learn gospel doctrines and principles essential to the work of redeeming the dead and how to find information about your ancestors that is needed to perform saving ordinances for them. The Lord has revealed that a great missionary effort is under way in the spirit world (see D&C 138:28–37). You become part of this great work when you identify your ancestors who did not receive the essential gospel ordinances in this life. It is your privilege to be baptized, confirmed, endowed, and sealed in their behalf in the temple, and males may receive the Melchizedek Priesthood for deceased males there. In this way all of our Heavenly Father’s children can come unto Christ and be perfected in Him.
President Wilford Woodruff (1807–98) spoke about the significance of the work of redeeming the dead: “I wish many times that the veil were lifted off the face of the Latter-day Saints. I wish we could see and know the things of God as they do who are laboring for the salvation of the human family who are in the spirit world; for if this were so, this whole people, with very few, if any, exceptions, would lose all interest in the riches of the world, and instead thereof their whole desires and labors would be directed to redeem their dead, to perform faithfully the work and mission given us on earth; so that when we ourselves should pass behind the veil and meet with Joseph and the ancient apostles, and others who are watching over us and who are deeply interested in our labors, we might feel satisfied in having done our duty” (The Discourses of Wilford Woodruff, ed. G. Homer Durham , 152)."