Mormonism teaches that the Holy Ghost is the third member of the godhead, but not equal to Heavenly Father. “He is a personage of Spirit, not having a body of flesh and bones.” (True to the Faith, p. 81) The Holy Ghost performs several roles in the plan of salvation, namely revealing truth and sanctifying those who have been worthy in carrying out the process of repentance.
The LDS Church teaches that the gift of the Holy Ghost can influence those who honestly and sincerely seek the truth. For instance, He will confirm that the Book of Mormon is true and Joseph Smith is the true prophet. At confirmation, a Mormon will receive the gift of the Holy Ghost. This means a person now has the right to have His constant companionship, but only if the Mormon is obedient in keeping the covenant promises. The Holy Ghost will be a guide in decision-making and offer protection from spiritual danger.
Biblical Christianity teaches:
Holy Spirit is God, equal to the Father and the Son. His knowledge, power, and presence have no limits. The work of the Holy Spirit is essential to life and salvation. Due to our sinful nature, we are unable to love or trust God. The Holy Spirit convicts us of our sin and need for Christ’s redemptive work. Saving faith in Jesus would be impossible without the Holy Spirit working through His Word.