Physical death is the separation of the spirit from the mortal body. The Fall of Adam brought physical death into the world (see Moses 6:48).
Death is an essential part of Heavenly Father’s plan of salvation (see 2 Nephi 9:6). In order to become like our Eternal Father, we must experience death and later receive perfect, resurrected bodies.
When the physical body dies, the spirit continues to live. In the spirit world, the spirits of the righteous “are received into a state of happiness, which is called paradise, a state of rest, a state of peace, where they shall rest from all their troubles and from all care, and sorrow” (Alma 40:12). A place called spirit prison is reserved for “those who [have] died in their sins, without a knowledge of the truth, or in transgression, having rejected the prophets” (D&C 138:32). The spirits in prison are “taught faith in God, repentance from sin, vicarious baptism for the remission of sins, the gift of the Holy Ghost by the laying on of hands, and all other principles of the gospel that [are] necessary for them to know” (D&C 138:33–34). If they accept the principles of the gospel, repent of their sins, and accept ordinances performed in their behalf in temples, they will be welcomed into paradise.
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 Corinthians 15:22). 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).
You have probably experienced the pain that comes at the death of a family member or friend. It is natural to feel sorrow at such times. In fact, mourning is one of the deepest expressions of love. The Lord said, “Thou shalt live together in love, insomuch that thou shalt weep for the loss of them that die” (D&C 42:45). The only way to take sorrow out of death is to take love out of life.
Even as you mourn at the death of loved ones, you can receive comfort in the promise of resurrection and in the assurance that families can be together forever. You can “see the great reason of sorrow, and also of rejoicing—sorrow because of death and destruction among men, and joy because of the light of Christ unto life” (Alma 28:14; see also verses 9–13).
In addition to receiving comfort when loved ones die, you can be at peace with the knowledge that you will eventually die. As you live the gospel, you can remember the Lord’s promise: “Those that die in me shall not taste of death, for it shall be sweet unto them” (D&C 42:46).