The third member of the Godhead is the personage referred to by members of The Church of Jesus Christ of Latter-day Saints as the Holy Ghost. Mormons believe that both God the Father and Jesus Christ have perfect, resurrected bodies of flesh and bone, glorious beyond description. However, the Holy Ghost is a personnage of spirit. It is the Holy Ghost who can dwell within us as a testator and comforter. Through the Holy Ghost, we can receive inspiration and personal revelation from God.
- The first Mormon prophet, Joseph Smith, taught: "The Father has a body of flesh and bones as tangible as man's; the Son also; but the Holy Ghost has not a body of flesh and bones, but is a personage of Spirit. Were it not so, the Holy Ghost could not dwell in us" (Doctrine and Covenants 130:22). In a figurative sense, the Holy Ghost dwells in the hearts of righteous Saints of all dispensations (Doctrine and Covenants 20:18-21).
The Holy Ghost is also known by various other names, such as the Holy Spirit, Spirit of God, Spirit of the Lord, and the comforter. A careful reading of the scriptures teaches that the Holy Ghost is provided as a witness of truth. The Book of Mormon teaches that the Holy Ghost is "the gift of God unto all those who diligently seek him, as well in times of old as in the time that he should manifest himself unto the children of men…. For he that diligently seeketh shall find; and the mysteries of God shall be unfolded unto them, by the power of the Holy Ghost, as well in these times as in times of old, and as well in times of old as in times to come" (1 Nephi 10:17-19).
When someone joins the Mormon Church, he normally receives the gift of the Holy Ghost as a separate ordinance through the laying on of hands shortly after his baptism. The Holy Ghost can have a great effect in a person's life, provided he lives worthy to have the Holy Ghost as his companion. (Mormons believe, consistent with scripture, that the Holy Ghost will not remain with an unclean or unworthy person.) In the lives of individuals, the Holy Ghost performs four very important functions:
- Sanctifier. Because no unclean thing can dwell in a divine presence, the whole system of salvation centers on the process of sanctification; people are saved to the extent that they are sanctified. To be sanctified means to become clean and pure; to become a new creature in Christ, and to have one's body renewed by the rebirth of the Spirit.
- Revelator. Joseph Smith taught that "no man can receive the Holy Ghost without receiving revelations" (Teachings of the Prophet Joseph Smith, p. 328). To enjoy the companionship of the Holy Ghost is to enjoy the spirit of revelation (Doctrine and Covenants 8:2-3). The Holy Ghost is the source of all saving knowledge. Those who sincerely and prayerfully seek this knowledge are promised that everything expedient will be revealed to them.
- Teacher. All who will be saved must be tutored by the Holy Ghost. The things of the Spirit can only be understood when taught and learned by the Spirit (Doctrine and Covenants 50:11-24). The divine commission to teach the truths of salvation rests with the Holy Ghost. Jesus was filled with the power of the Holy Ghost (Luke 4:1). The Father gave Christ the Spirit without measure (John 3:34). Angels also speak by the power of the Holy Ghost (2 Nephi 32:3).
- Comforter. A distinctive characteristic of the truths of salvation is that they are attended by a spirit of comfort and peace. It is the duty of the Holy Ghost to lift burdens, give courage, strengthen faith, grant consolation, extend hope, and reveal whatever is needed to those having claim on his sacred companionship (Moses 6:61).
The Holy Ghost is such an uplifting power and source of necessary gospel knowledge that to have his constant companionship and influence is the greatest gift a person can receive in mortality. Because of the Holy Ghost's importance in God's plan of salvation, Jesus taught that no sin is greater than the sin against the Holy Ghost (Matthew 12:31-32). A latter-day revelation explains that "blasphemy against the Holy Ghost, which shall not be forgiven in the world nor out of the world, is in that ye commit murder wherein ye shed innocent blood, and assent unto my death, after ye have received my new and everlasting covenant, saith the Lord God" (Doctrine and Covenants 132:27). This is understood to mean that once a person receives a personal witness that Jesus is the Christ -- that is, that Christ manifests himself to the person through the power of the Holy Ghost -- if the person then denies the Christ, it is as if he was crucifying Christ anew. This is the sin against the Holy Ghost.