For Latter-day Saints, the endowment serves as a rite of adult initiation. Growing out of Joseph Smith's encounter with Freemasonry, the endowment is a ritual drama re-enacting the scriptural narrative of the creation and the fall and pre-enacting the safe return of the faithful into God's presence. In the course of the ceremony, initiates are washed, anointed, and clothed in a sacred protective garment. They covenant to lead lives of modesty, temperance, reverence, fidelity, charity, sacrifice, and consecration. They don priestly robes and learn the sacred signs, tokens, and keywords which, they are told, will give them access to God's presence in the next life if they faithfully live out their covenants in this one.
The endowment has two parts: the initiatory (a rite of washing, anointing, and clothing in the temple garment) and the ritual drama (which I dub the endowment proper--it is this that Latter-day Saints usually have in mind when they speak of "the endowment"). In the earliest LDS temples, the endowment's ritual drama required participants to move through a series of rooms, representing the creation, the garden of Eden, the telestial world, and the terrestrial world. The ritual's climax occurs when initiates are ushered through a veil into the celestial room, representing the presence of God.
Other temple ordinances connected to the endowment are the sealing rites (which eternally unite spouses and their children) and the second anointing (a rarely administered rite that builds on promises made during the initiatory).
The endowment has evolved considerably from the rite Joseph Smith first adminstered to an inner circle of his followers on the upper floor of his Nauvoo store in 1842. The ritual drama of the creation and the fall was not developed until after Smith's death; the ceremony was not committed to written form until near the end of Brigham Young's life; and a standard script for use in all temples was not produced until the 1920s. Throughout its history, the ceremony has undergone periodic changes in language, structure, and presentation--including, in the 1950s, the shift from live endowments to film. In 1990, the endowment proper underwent a sweeping revision that, among other things, streamlined the two-hour ceremony and eliminated certain Masonic elements, including the infamous penalties. Procedures for the initiatory were revised in January 2005 to eliminate vestiges of ritual nudity that had survived from the nineteenth century.
Whatever its interest to researchers, the endowment is meant to be a profoundly meaningful religious experience for initiates. The ceremony promotes in Latter-day Saints a vivid sense of belonging to a priestly people--called to holiness, consecrated to God's service, and empowered to do the work of Christ, in whose likeness they are anointed. The endowment reflects the Saints' covenant-based theology, their faith in an organized cosmos, their belief in the divine nature of every human being. It invites initiates to see life as an ongoing process of learning and growth: learning by experience and revelation; growth into the measure of one's creation and thus into a fullness of joy. The symbols of the endowment have played a key role in shaping my own sense of who I am and what I am meant to do with my life.