Mormons believe he holds the sealing power of the Melchizedek priesthood. They believe he appeared to Joseph Smith and Oliver Cowdery in the Kirtland Temple in fulfillment of Malachi 4:5,6. Mormons claim he conferred on Smith and Cowdery the keys of this sealing power, which especially includes the power to perform ordinances for the dead (D&C 110:13-16).
Dictionary of "Mormonese"
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