No death during the millennium

The LDS Church defines physical death in its Guide to the Scriptures as "the separation of the body and the spirit." The First Presidency, in its "doctrinal guidebook" (indentified as such in Ensign, Apr. 2004, p.79), elaborates:

"When the physical body dies, the spirit continues to live....

"Because of the Atonement and Resurrection of Jesus Christ, physical death is only temporary: 'As in Adam all die, even so in Christ shall all be made alive' (1 Cor. 5:22). Everyone will be resurrected, meaning that every person's spirit will be reunited with his or her body—'restored to their proper and perfect frame' and no longer subject to death (Alma 40:23; see also Alma 11:44–45)." (True to the Faith, pp.46-47.)

Being "changed in the twinkling of an eye from mortality to immortality" (3 Ne 28:8) is not death as described above. For example, during that change the body "shall not sleep, that is to say in the earth, but shall be changed in the twinkling of an eye." (D&C 101:31.) Thus this change involves both death and resurrection. In fact, it is a transition directly through death to resurrection. This change, therefore, is not the death spoken of in D&C 101:29 which says that during the Millennium "there shall be no sorrow because there is no death."