This information straight from Salt Lake City:
36863, True to the Faith, Cross, 45-46
The cross is used in many Christian churches as a symbol of the Savior’s death and Resurrection and as a sincere expression of faith. As members of The Church of Jesus Christ of Latter-day Saints, we also remember with reverence the suffering of the Savior. But because the Savior lives, we do not use the symbol of His death as the symbol of our faith.
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The only members of the Church who wear the symbol of the cross are Latter-day Saint chaplains, who wear it on their military uniforms to show that they are Christian chaplains.
See also Atonement of Jesus Christ; Jesus Christ; Resurrection