A body buried in a wooden casket would normally be entirely decomposed after a few hundred years, depending upon the conditions of the soil. Similarly, a seaman buried at sea would leave no traces. (Not a trace seems to remain of all of those who went down with the Titanic, for instance.)
The apostle Paul made it clear that our new body, though possessing some identity with our mortal body, will be a new “spiritual body” ( 1 Corinthians 15:35-44 ). God will not need to gather up the scattered molecules of our earthly bodies. (Remember that the bodies of many Christians have already decomposed, been completely destroyed by fire, or have been devoured by animals.) Therefore, 1 Thessalonians 4:13-18 doesn’t refer to a bizarre scene in which the ashes in funerary urns or decayed bodies in earthly graves are suddenly reconstituted. Rather, the resurrection is the wonderful occasion in which believers who have died will again be granted full bodily form, this time in a glorified heavenly body that can never again die or experience decay.
Does Isaiah 65:17 imply that people in heaven will have no recollection of earthly events?
Isaiah 65:17 (ESV) states: “I create new heavens and a new earth, and the former things shall not be remembered or come into mind.” What are the “former things” that “shall not be remembered or come into mind”? First Corinthians 13 tells us that in glory we will no longer see “as through a glass darkly” but we will “know as we are known.”
“For we know in part and we prophesy in part, but when perfection comes, the imperfect disappears. When I was a child, I talked like a child, I thought like a child, I reasoned like a child. When I became a man, I put childish ways behind me. Now we see but a poor reflection as in a mirror; then we shall see face to face. Now I know in part; then I shall know fully, even as I am fully known” (1 Corinthians 13:9-12 NIV).
When the resurrected Christ in His glorified body appeared to Thomas, Jesus still bore the marks of the Roman nails and spear (John 20:24-29). If in heaven we were unable to remember our lives here—including our sins—we would neither have a clear understanding of who we had been, nor an awareness of the worth of our redemption.
In heaven, our perspective will no longer be dominated by “former things.” Knowledge of past sins or earthly suffering will not cause the same kind of suffering and emotional anguish in heaven that it does now. We will see how God’s grace has healed all of the scars that sin left on our mortal lives. We will see how God’s grace could even use our repented sins to bring about His good purposes.
While there is so much we don’t know about the happiness of heaven, for now we can probably safely assume that, at the very least, “no knowledge of former things” means that we will not be dominated by memories of those things that are so painful and destructive now. As implied by Isaiah 65:17, the transformation that will occur in the new heavens and new earth will be so complete that our perspective will be utterly changed. Our earlier, fallen perspective will “not be remembered or come into mind.” The dark and tragic aspects of our past lives will be transformed by the light of a glorious new reality, filled with gratitude and joy.