The Holy Ghost is the third member of the Godhead. He does not have a body of flesh and bone but is a spirit in the form of a man. He can be in only one place at a time, but his influence can be everyplace at the same time. His mission is to bear testimony of Heavenly Father and Jesus Christ as well as to bear witness of all truth.
The Holy Ghost and the gift of the Holy Ghost is not the same thing. The gift of the Holy Ghost is a privilege given to a baptized member when he is confirmed a member of The Church of Jesus Christ of Latter-day Saints. This gift is given to baptized members to receive guidance and inspiration from the Holy Ghost. Members of the Church must be worthy in order to receive revelation and to enjoy the companionship of the Holy Ghost.
Anyone may be temporarily guided by the Holy Ghost without receiving the Holy Ghost, but the person will not continue to receive this guidance if they do not receive baptism and the gift of the Holy Ghost. This truth is illustrated in Acts 10 when the roman soldier Cornelius received inspiration from the Holy Ghost so that he knew the gospel of Jesus Christ was true. Cornelius did not receive the gift of the Holy Ghost until after he was baptized. If he had not received baptism and the gift of the Holy Ghost, the Holy Ghost would have left him. Today, non-members of the Church learn, by the power of the Holy Ghost, that the Book of Mormon – Another Testament of Jesus Christ is true (see Moroni 10:4-5). If they do not act upon that flash of testimony and receive baptism and the gift of the Holy Ghost, they will not receive the continuing assurance they might have received.
The gift of the Holy Ghost is given through the laying on of hands by the elders of the Church after a person has been baptized and confirmed a member of the Church. Every worthy elder of the Church may bestow the gift of the Holy Ghost to another person when properly authorized. The person, however, does not receive a guarantee of inspiration and guidance simply because the elders have laid their hands on his head. Each person must “receive the Holy Ghost.” This means that the Holy Ghost will only come to those who are worthy and who desire help from this heavenly messenger.
To be worthy to have the companionship of the Holy Ghost, one must be striving to obey all of the commandments of God. He must keep his thoughts and actions pure. President David O. McKay taught “One chief purpose of life is to overcome evil tendencies, to govern our appetites, to control our passions – anger, hatred, jealousy, immorality. We have to overcome them; we have to subject them, conquer them because God has said: `… the Spirit of the Lord doth not dwell in unholy temples –’ (Helaman 4:24), nor will it `… always strive with man’
(2 Nephi 26:11).” (See “Emotional Maturity,” Instructor, Sept. 1959, p. 281, as quoted in Gospel Principles, p. 102.)
The gift of the Holy Ghost is one of the greatest gifts of God. Through this great gift we can know for ourselves that Heavenly Father lives, that Jesus is the Christ, and that His Church has been restored to the earth. Through this gift we can receive promptings from the Holy Ghost to tell us all the things we should do (see 2 Nephi 32:5). Through this gift we can enjoy other gifts of the Spirit. This gift can bring peace to our hearts and help us understand the things of God (1 Corinthians 2:9-12).