“When used together, the Bible and the Book of Mormon confound false doctrines”
Tad R Callister, Of the Presidency of the Seventy, The Book of Mormon—a Book from God
“But why is the Book of Mormon so essential if we already have the Bible to teach us about Jesus Christ? Have you ever wondered why there are so many Christian churches in the world today when they obtain their doctrines from essentially the same Bible? It is because they interpret the Bible differently. If they interpreted it the same, they would be the same church. This is not a condition the Lord desires, for the Apostle Paul declared that there is “one Lord, one faith, one baptism” (Ephesians 4:5). To help bring this oneness about, the Lord established a divine law of witnesses. Paul taught, “In the mouth of two or three witnesses shall every word be established” (2 Corinthians 13:1).
The Bible is one witness of Jesus Christ; the Book of Mormon is another. Why is this second witness so crucial? The following illustration may help: How many straight lines can you draw through a single point on a piece of paper? The answer is infinite. For a moment, suppose that single point represents the Bible and that hundreds of those straight lines drawn through that point represent different interpretations of the Bible and that each of those interpretations represents a different church.
What happens, however, if on that piece of paper there is a second point representing the Book of Mormon? How many straight lines could you draw between these two reference points: the Bible and the Book of Mormon? Only one. Only one interpretation of Christ’s doctrines survives the testimony of these two witnesses.”