Alma 13:12; 3 Ne. 12:2; John 3:3-5; Luke 3:16; Moses 6:66; Teachings of the Book of Mormon, Barrett, p. 93; refer in this text to 3 Ne. 27:20
“You might as well baptize a bag of sand as a man, if not done in view of the remission of sins and getting of the Holy Ghost. Baptism by water is but half a baptism, and is good for nothing without the other half — that is, the baptism of the Holy Ghost.” (Teachings of the Prophet Joseph Smith, p. 366)
“The Holy Ghost is a sanctifier (Alma 13:12; 3 Nephi 27:19-20). The ordinance of baptism consists of two parts: the baptism of water and the baptism of fire or the Holy Ghost (see John 3:3-5). The Holy Ghost is the sanctifying medium by which one’s sins—after the outward ordinances—may be purged, as though by fire.” (R. Millet and J. F. McConkie, Doctrinal Commentary on The Book of Mormon, 1:366)
“Sins are remitted not in the waters of baptism, as we say in speaking figuratively, but when we receive the Holy Ghost… . The baptism of the Holy Ghost is the baptism of fire… . After baptism in water, legal administrators lay their hands upon a repentant person and say: ‘Receive the Holy Ghost.’ This gives him the gift of the Holy Ghost, which is the right to the constant companionship of that member of the Godhead based on faithfulness. Either then or later, depending upon the individual’s personal worthiness, the Holy Ghost comes. The baptized person becomes a new creature. He is baptized with fire, sin and evil are burned out of his soul, and he is born again.” (Bruce R. McConkie, A New Witness for the Articles of Faith, pp. 290-291)
“Water baptism is only a preparatory cleansing of the believing penitent … whereas, the baptism of fire and the Holy Ghost cleanses more thoroughly, by renewing the inner man, and by purifying the affections, desires, and thoughts which have long been habituated in the impure ways of sin.” (Orson Pratt, The Holy Spirit, pp. 56-57)