In Mormonism, the fulness of the gospel refers to the complete system of laws, ordinances, covenants, and priesthood authority necessary for exaltation. It includes everything restored through Joseph Smith that had supposedly been lost during the Great Apostasy.
While the Bible is valued, Mormons believe that the fulness of God’s truth is found only within The Church of Jesus Christ of Latter-day Saints, which they regard as the restored and only true church on earth. This fulness encompasses temple covenants, priesthood authority, modern revelation, and the Book of Mormon as additional scripture.
Biblical Christianity teaches that the gospel is already full and complete. It is the good news that Jesus Christ has done everything necessary for our salvation. Nothing can be added to or restored to the message of grace. The “fulness” of the gospel is found in Christ himself, who accomplished our redemption once for all through his life, death, and resurrection (Colossians 2:9–10; Hebrews 10:10).
