The Holy Ghost is the third member of the Godhead. He is a personage of spirit, without a body of flesh and bones (see D&C 130:22). He is often referred to as the Spirit, the Holy Spirit, the Spirit of God, the Spirit of the Lord, or the Comforter.
The Holy Ghost works in perfect unity with Heavenly Father and Jesus Christ, fulfilling several roles to help you live righteously and receive the blessings of the gospel.
He “witnesses of the Father and the Son” (2 Nephi 31:18) and reveals and teaches “the truth of all things” (Moroni 10:5). You can receive a sure testimony of Heavenly Father and Jesus Christ only by the power of the Holy Ghost. His communication to your spirit carries far more certainty than any communication you can receive through your natural senses.
As you strive to stay on the path that leads to eternal life, the Holy Ghost “will show unto you all things what [you] should do” (see 2 Nephi 32:1–5). He can guide you in your decisions and protect you from physical and spiritual danger. Through Him, you can receive gifts of the Spirit for your benefit and for the benefit of those you love and serve (see D&C 46:9–11).
He is the Comforter (John 14:26). As the soothing voice of a loving parent can quiet a crying child, the whisperings of the Spirit can calm your fears, hush the nagging worries of your life, and comfort you when you grieve. The Holy Ghost can fill you “with hope and perfect love” and “teach you the peaceable things of the kingdom” (Moroni 8:26; D&C 36:2).
He is the Holy Spirit of Promise (see Ephesians 1:13; D&C 132:7, 18–19, 26). In this capacity, He confirms that the priesthood ordinances you have received and the covenants you have made are acceptable to God. This approval depends on your continued faithfulness.
All honest seekers of the truth can feel the influence of the Holy Ghost, leading them to Jesus Christ and His gospel. However, the fulness of the blessings given through the Holy Ghost are available only to those who receive the gift of the Holy Ghost and remain worthy.
After you were baptized into The Church of Jesus Christ of Latter-day Saints, one or more Melchizedek Priesthood holders laid their hands on your head and, in a sacred priesthood ordinance, confirmed you a member of the Church. As part of this ordinance, called confirmation, you were given the gift of the Holy Ghost.
The gift of the Holy Ghost is different from the influence of the Holy Ghost. Before your baptism, you could feel the influence of the Holy Ghost from time to time, and through that influence you could receive a testimony of the truth. Now that you have the gift of the Holy Ghost, you have the right to the constant companionship of that member of the Godhead if you keep the commandments.
Full enjoyment of the gift of the Holy Ghost includes receiving revelation and comfort, serving and blessing others through spiritual gifts, and being sanctified from sin and made fit for exaltation in the celestial kingdom. These blessings depend on your worthiness; they come a little at a time as you are ready for them. As you bring your life in harmony with God’s will, you gradually receive the Holy Ghost in great measure. The Prophet Joseph Smith declared that the mysteries of God’s kingdom “are only to be seen and understood by the power of the Holy Spirit, which God bestows on those who love him, and purify themselves before him” (see D&C 76:114–116).
Remember that “the Spirit of the Lord doth not dwell in unholy temples” (Helaman 4:24). Even though you have received the gift of the Holy Ghost, the Spirit will dwell with you only when you keep the commandments. He will withdraw if you offend Him by profanity, uncleanliness, disobedience, rebellion, or other sins. Keep yourself clean. Fill your life with goodness so you can be worthy of the constant companionship of the Holy Ghost.