2 Nephi 31:13-17
Speaking of this baptism of fire, Elder Bruce R. McConkie explained as follows:

"By the power of the Holy Ghost who is the Sanctifier (3 Ne. 27:19-21)—dross, iniquity, carnality, sensuality, and every evil thing is burned out of the repentant soul as if by fire; the cleansed person becomes literally a new creature of the Holy Ghost. (Mosiah 27:24-26.) He is born again.
"The baptism of fire is not something in addition to the receipt of the Holy Ghost; rather, it is the actual enjoyment of the gift which is offered by the laying on of hands at the time of baptism. 'Remission of sins,' the Lord says, comes 'by baptism and by fire, yea, even the Holy Ghost.' (D. & C. 19:31; 2 Ne. 31:17.) Those who receive the baptism of fire are 'filled as if with fire.' (Hela. 5:45.)"

(Mormon Doctrine, p. 73.)

Ephesians 1:13
"Sealed with That Holy Spirit of Promise"
President Joseph Fielding Smith--

"The Holy Spirit of Promise is the Holy Ghost who places the stamp of approval upon every ordinance: baptism, confirmation, ordination, marriage. The promise is that the blessings will be received through faithfulness. New Testament Student Study Guide, p.135 "If a person violates a covenant, whether it be of baptism, ordination, marriage or anything else, the Spirit withdraws the stamp of approval, and the blessings will not be received"

(Doctrines of Salvation, 1:45; see also D&C 132:7)

"I am not surprised that comparatively few people join the Church from among the large number on whom the missionaries call. There's no faith. On the other hand, I am amazed that so many do. It is a marvelous and wonderful thing that thousands are touched by the miracle of the Holy Spirit, that they believe and accept and become members. They are baptized. Their lives are forever touched for good. Miracles occur. A seed of faith comes into their hearts. It enlarges as they learn. And they accept principle upon principle, until they have every one of the marvelous blessings that come to those who walk with faith in this, The Church of Jesus Christ of Latter-day Saints."

(Gordon B. Hinckley, "The Miracle of Faith," Ensign, May 2001, 68)