In family home evening, my son and daughter-in-law taught their children – the oldest of whom is 4-year-old Joshua – that a person has two components: a spirit which comes from Heavenly Father and a physical body. They further taught that when a person dies, the spirit goes back to Heavenly Father, and we don't see him or her again until we die.
Shortly after this lesson the family moved from the neighborhood where Joshua had spent his entire four years. When they came to load up the last of their possessions, Joshua's friends came to see him one last time. As they got in the car to leave, Joshua, realizing that he would not see his friends again, smiled, waved and said, "See you when we die."