"The other Comforter spoken of is a subject of great interest, and perhaps understood by few of this generation. After a person has faith in Christ, repents of his sins, and is baptized for the remission of his sins and receives the Holy Ghost, (by the laying on of hands), which is the first Comforter, then let him continue to humble himself before God, hungering and thirsting after righteousness, and living by every word of God, and the Lord will soon say unto him, Son, thou shalt be exalted. When the Lord has thoroughly proved him, and finds that the man is determined to serve Him at all hazards, then the man will find his calling and his election made sure, then it will be his privilege to receive the other Comforter, which the Lord hath promised the Saints, as is recorded in the testimony of St. John, in the 14th chapter, from the 12th to the 27th verses.
"Note the 16, 17, 18, 21, 23 verses:
"And I will pray the Father, and He shall give you another Comforter, that he may abide with you forever; Even the Spirit of Truth; whom the world cannot receive, because it seeth him not, neither knoweth him; but ye know him; for he dwelleth with you, and shall be in you.
"I will not leave you comfortless: I will come to you. * * * He that hath my commandments, and keepeth them, he it is that loveth me: and he that loveth me should be loved of my Father, and I will love him, and will manifest myself to him. If a man love me, he will keep my words: and my Father will love him, and we will come unto him, and make our abode with him."
"Now what is this other Comforter? It is no more nor less that the Lord Jesus Christ Himself; and this is the sum and substance of the whole matter; that when any man obtains this last Comforter, he will have the personage of Jesus Christ to attend him, or appear unto him from time to time, and even He will manifest the Father unto him, and they will take up their abode with him, and the visions of the heavens will be opened unto him, and the Lord will teach him face to face, and he may have a perfect knowledge of the mysteries of the Kingdom of God; and this is the state and place the ancient Saints arrived at when they had such glorious visions—Isaiah, Ezekiel, John upon the Isle of Patmos, St. Paul in the three heavens, and all the Saints who held communion with the general assembly and Church of the First Born." (Joseph Smith, HC 3:25, p. 380-381)