The Spirit of God speaking to the spirit of man has power to impart truth with greater effect and understanding than the truth can be imparted by personal contact even with heavenly beings. Through the Holy Ghost the truth is woven into the very fibre and sinews of the body so that it cannot be forgotten.
We believe the Holy Ghost is a revelator and that he will bear testimony to honest people everywhere that Jesus Christ is the Son of God, that Joseph Smith is a prophet, and that this church is “the only true and living church upon the face of the whole earth.” (D&C 1:30.)
There is no need for anyone to remain in darkness; the light of the everlasting gospel is here; and every sincere investigator on earth can gain a personal witness from the Holy Spirit of the truth and divine nature of the Lord’s work.
These excerpts taken from Teachings of Presidents of the Church: Joseph Fielding Smith, Chapter 14, The Gift of the Holy Ghost.