2 Nephi 25-26
The Book of Mormon is the keystone of our religion. This was the Prophet Joseph Smith’s statement. He testified that “the Book of Mormon was the most correct of any book on earth, and the keystone of our religion” (Introduction to the Book of Mormon). A keystone is the central stone in an arch. It holds all the other stones in place, and if removed, the arch crumbles.
There are three ways in which the Book of Mormon is the keystone of our religion. It is the keystone in our witness of Christ. It is the keystone of our doctrine. It is the keystone of testimony.
The Book of Mormon is the keystone in our witness of Jesus Christ, who is Himself the cornerstone of everything we do. It bears witness of His reality with power and clarity. Unlike the Bible, which passed through generations of copyists, translators, and corrupt religionists who tampered with the text, the Book of Mormon came from writer to reader in just one inspired step of translation. Therefore, its testimony of the Master is clear, undiluted, and full of power. But it does even more. Much of the Christian world today rejects the divinity of the Savior. They question His miraculous birth, His perfect life, and the reality of His glorious resurrection. The Book of Mormon teaches in plain and unmistakable terms about the truth of all of those. It also provides the most complete explanation of the doctrine of the Atonement. Truly, this divinely inspired book is a keystone in bearing witness to the world that Jesus is the Christ (see title page of the Book of Mormon).
The Book of Mormon is also the keystone of the doctrine of the Resurrection. As mentioned before, the Lord Himself has stated that the Book of Mormon contains the “fulness of the gospel of Jesus Christ” (D&C 20:9). That does not mean it contains every teaching, every doctrine ever revealed. Rather, it means that in the Book of Mormon we will find the fulness of those doctrines required for our salvation. And they are taught plainly and simply so that even children can learn the ways of salvation and exaltation. The Book of Mormon offers so much that broadens our understandings of the doctrines of salvation. Without it, much of what is taught in other scriptures would not be nearly so plain and precious.
Finally, the Book of Mormon is the keystone of testimony. Just as the arch crumbles if the keystone is removed, so does all the Church stand or fall with the truthfulness of the Book of Mormon. The enemies of the Church understand this clearly. This is why they go to such great lengths to try to disprove the Book of Mormon, for if it can be discredited, the Prophet Joseph Smith goes with it. So does our claim to priesthood keys, and revelation, and the restored Church. But in like manner, if the Book of Mormon be true—and millions have now testified that they have the witness of the Spirit that it is indeed true—then one must accept the claims of the Restoration and all that accompanies it.
Yes, my beloved brothers and sisters, the Book of Mormon is the keystone of our religion—the keystone of our testimony, the keystone of our doctrine, and the keystone in the witness of our Lord and Savior. (“The Book of Mormon—Keystone of Our Religion,” Ensign, Nov. 1986).