Baptism by immersion performed by a living person acting on behalf of one who is dead, as practiced in New Testament times (1 Corinthians 15:29). This ordinance is performed in temples of The Church of Jesus Christ of Latter-day Saints.
Amy Harris, “How Family History Changes Our Hearts and Minds,” Liahona, February 2015
LaRene Porter Gaunt, “Covenants: Two-Way Promises with God,” Ensign, April 2014
Susan Easton Black, “A Voice of Gladness,” Ensign, February 2004
“Blessings Await in the Temple,” Church News