President Ezra Taft Benson said at April 1987 general conference: "The Book of Mormon is the `keystone' of our religion, and the Doctrine and Covenants is the capstone, with continuing latter-day revelation. The Lord placed his stamp of approval on both the keystone and the capstone."
These two volumes of scripture complement one another. The coming forth of the Book of Mormon impacted the Doctrine and Covenants.For example, Moroni's visit to Joseph Smith in September of 1823, which marked the prophet's introduction to the Book of Mormon, was also the occasion for the first chronological revelation, found in Section 2 in the Doctrine and Covenants.
In addition, activity in translating the Book of Mormon was associated with the reception of revelations found in the Doctrine and Covenants.
Note the following relationships between the Book of Mormon and the Doctrine and Covenants:
In D&C 1:17,29, the Lord bears testimony that Joseph was His servant and the Book of Mormon was translated by the " . . . power of God . . . ."
In D&C 42:12, the Lord tells us to teach from the Bible and the Book of Mormon, " . . . in the which is the fulness of the gospel."
In D&C 84:57, the Lord says Church members are under condemnation until they remember the Book of Mormon.
The Doctrine and Covenants is an extension of the stick of Ephraim (See Ezek. 37:16-17) and has been welded together as one stick with the Book of Mormon. - Hoyt W. Brewster Jr., managing director of the Church's Priesthood Department