All true religion is revealed religion and its truths must be taught by the spirit of revelation. We are told that should a gospel truth be taught independent of that spirit “it is not of God” (D&C 50:13-18).
This explains the necessity, as Nephi has been teaching, of baptism and receiving the gift of the Holy Ghost, for the Holy Ghost is a revelator, and as Joseph Smith said, “No man can receive the Holy Ghost without receiving revelations” (Teachings, p. 328).