One core tenet of LDS scriptures is the belief that the Church removed important truths from the Bible. If the modern Bible is untrustworthy, additional scriptures are needed to restore the truth that was lost. Joseph Smith plainly stated this need in the 8th Article of Faith: "We believe the Bible to be the word of God as far as it is translated correctly; we also believe the Book of Mormon to be the word of God."1
In 1 Nephi 13, the prophet Nephi had a vision of an uncorrupted book that contained the fullness of God's Word (v.20-24). However, after the Bible was completely recorded and the apostles died, the "great and abominable church," founded by the devil (v.6), deliberately removed many "plain and most precious" truths (v.26-28) in the transmission of the Bible. Therefore, Satan has great power over those who are mindlessly following the teachings of the Church (v.29).2
Joseph Smith claimed this great conspiracy necessitated additional Scripture (Book of Mormon, Doctrine and Covenants, Pearl of Great Price). It showed the need for modern prophets. Smith also began work on the Joseph Smith Translation (JST), also called "The Inspired Version of the Holy Scriptures."
He claimed that this translation was the restoration of the plain and precious portions of the Bible. He did not consult Greek or Hebrew texts but referenced the King James Version of the Bible.3
JST vs. Ancient Manuscripts
However, we must address a glaring problem with this claim. In the 1830s, people did not have access to the wealth of manuscript evidence we have today. Serious archaeological disciplines did not become prevalent until the mid-to-late 1800s. The most significant biblical discoveries occurred much later as technology and interest progressed. For example, the Dead Sea Scrolls were discovered in 1946, over a century after Joseph Smith's translation.
Let's look at just one verse that tests the validity of the Joseph Smith Translation. The most complete Isaiah scroll in the Dead Sea Scrolls (1QIsaa) was written ca. 125 B.C. and contains all 66 chapters of Isaiah. If portions of Scripture were removed after the apostles' deaths and Joseph Smith restored those plain and precious truths, then the words from the JST should be in the Great Isaiah Scroll.
Let's look at Isaiah 29:13 as an example:
King James Version: "Wherefore the Lord said, Forasmuch as this people draw near me with their mouth, and with their lips do honour me, but have removed their heart far from me, and their fear toward me is taught by the precept of men."
Joseph Smith Translation: "Wherefore the Lord said, Forasmuch as this people draw near me with their mouth, and with their lips do honor me, but they have removed their hearts far from me, and their fear toward me is taught by the precept of men, therefore, I will proceed to do a marvelous work among this people, yea, a marvelous work and a wonder; for the wisdom of their wise and learned shall perish, and the understanding of their prudent shall be hid."
A Literal English Translation of the Great Isaiah Scroll: "And the LORD said, Inasmuch as the people draw near to honor me with their mouth and with their lips, but have removed their hearts far from me, and fear of me has been like a human commandment that has been taught them."4
Why did Joseph Smith place those extra words in Isaiah 29:13? Because 2 Nephi 27:24-26; 29:1-2 predicts the coming Book of Mormon as the "marvelous work and wonder." It gives the Book of Mormon more credibility if the great prophet, Isaiah, foretold its coming.
Put It to the Test
That is just one example of thousands where the texts don't line up. The words of the Great Isaiah Scroll have been accurately transmitted to our Bibles today. No phrase of Joseph Smith's translation is present in any of the 25,000 Dead Sea scrolls and fragments or the thousands of other hand-written manuscripts that archaeologists have uncovered. If plain and precious truths have been removed, then we should have at least one manuscript that contains the missing words of the JST and supports Smith’s claim.
For the sake of argument, what if the book of Isaiah was corrupted shortly after it was written, and the true words of God are lost to history? Consider that the Great Isaiah Scroll, hand-copied more than a century before Jesus' birth, contained the same wording that He read from Isaiah 61 in the synagogue (Luke 4:16-21).
Was Jesus Himself reading and teaching the incomplete Scriptures? Was He fooled by an inaccurate document, altered by corrupt men? Of course not. He is the Word made flesh (John 1:14). He was reading God's Word as it was intended to be transmitted. We can confidently trust that God has preserved His Word (Isaiah 40:8).