Dean Helland, who is now a Christian missionary to Chile, was raised in a Fundamentalist Mormon sect (hundreds of different splinter groups exist in the world of Mormonism). His family moved among the various Mormon communions, including the Reorganized Church of Jesus Christ of Latter-day Saints. Finally, his father, convinced that all the Mormon expressions were impure, moved Dean and the family to Arizona to "take the Book of Mormon to the Lamanites."
     Dean's dad would take the family to a different Christian church each Sunday. Sometime during the service he would stand up and tell the congregation they needed the Book of Mormon if they were to be saved.
     As a young man, Dean was convinced the Book of Mormon was true. He had testimony of it. He challenged Christians to: "Show me one place where the Book of Mormon contradicts the Bible and I will lay down the Book of Mormon." He said no Christian ever accepted the challenge!
     Dean was so certain that God was leading him to write a book in defense of the Book of Mormon that he began a minute comparison of the Book of Mormon and the Bible to prove that the Book of Mormon restored the sense of the Bible, the "plain and precious parts of the gospel" destroyed by the Catholic Church (as the Book of Mormon teaches in I Nephi 13:26-40).
     As Dean compared passages from Isaiah with their parallel in the Book of Mormon, he said, "I came across a verse that made my heart leap." He had discovered a place where the Book of Mormon clearly made sense out of an obscure verse of Isaiah.
     The verse was Isaiah 2:9 (KJV), which Joseph Smith, the founder of Mormonism, had lifted out of the King James Bible, "corrected," and inserted in the Book of Mormon as II Nephi 12:9. Here are the two verses side by side.
Modern Book of Mormon
2 Nephi 12:9 And the mean man boweth not down, and the great man humbleth himself not, therefore, forgive him not. [Note: Actually the 1830 BoM was closer to being correct tha the modern, "corrected" version--though not much.]		 Bible
Isa 2:9 And the mean man boweth down, and the great man humbleth himself: therefore forgive them not.

     What Dean saw was that the Book of Mormon corrected the sense of the Bible. Joseph Smith straightened out the Book of Isaiah. If mean men don't bow down or great men don't humble themselves, in the interests of justice, they should not be forgiven.
      Dean left the verse elated. He returned to it a few days later to re-study it, "to savor the success of my discovery."
      But this time, he saw the verses in context. He discovered that Isaiah was not talking about men who will not bow down to God; on the contrary, he was talking about men who do bow down to idols! God is saying, in this passage, "both small and great men are bowing down to idols and I won't forgive them for it!"
     Dean said, "It hit me like a bolt of lightening," Dean said. "Joseph Smith made a common mistake: he failed to read in context. He 'corrected' the Bible, assuming he knew better than the Holy Spirit. It was obvious that the Bible was the correct text, and the Book of Mormon was wrong."

(This is excerpted from my book Have You Witnessed to a Mormon Lately?