In June of 1830, two months after the Church was organized, Joseph Smith began an inspired revision of the King James Bible — a project the Lord commissioned and that occupied him intermittently for the rest of his life, with the densest work falling between 1830 and 1833. The revision ranges from minor wording changes to substantial restorations of lost material, and it covers both Testaments.
Two substantial portions of the Joseph Smith Translation (often abbreviated JST) are canonized in the Latter-day Saint Standard Works. The Book of Moses in the Pearl of Great Price — eight chapters covering the opening of Genesis — is drawn directly from JST Genesis 1–6. Joseph Smith—Matthew, also in the Pearl of Great Price, is drawn from JST Matthew 24 (the Olivet Discourse). These portions were canonized in 1880 when the Pearl of Great Price itself was canonized; they have stood as scripture in the Latter-day Saint tradition ever since.
The rest of the JST is not canonized in the Latter-day Saint Standard Works, but it is available in two principal places. In the LDS edition of the King James Bible, JST revisions appear as footnotes throughout both Testaments, with a JST appendix at the back of the volume collecting longer JST passages that don’t fit in the footnote space. The Community of Christ (formerly the Reorganized Church of Jesus Christ of Latter Day Saints) has published the full JST since 1867 as the Inspired Version of the Holy Scriptures. The Joseph Smith Papers Project’s Revelations and Translations Series now provides a critical edition of the original manuscripts.
The JST reflects continuing revelation about the Biblical text. Some revisions restore material that the JST presents as having been lost from the ancient text; some clarify the wording of difficult passages; some harmonize passages that appear to disagree; and some are doctrinal clarifications. For Latter-day Saints, the JST is a substantial body of inspired work that stands alongside — and in places informs — the canonical reading of the Bible.