1 Thessalonians 4:14 (ESV) … “For since we believe that Jesus died and rose again, even so, through Jesus, God will bring with him those who have fallen asleep.”
What, then, does happen to those who put their faith in Christ but who die before the Lord returns? Paul reviews three things in answer to that question. First, our feelings are reviewed: “But I would not have you to be ignorant, brethren, concerning them which are asleep, that ye sorrow not, even as others which have no hope” (4:13). Death is indeed a hopeless tragedy for those who were outside of Christ, regarding both those who die and those who are left behind to mourn.
We have all attended funerals. As we stand before the casket and gaze into the cold, calm face of the corpse, we confront the terrible finality of death. We are confronted, too, with the utter insolvency of the human race.
The philosopher comes. He expounds his thoughts and theories concerning death. He quotes from the sages of the past, none of whom could speak with authority as to the reason for death or say with authority what lies beyond. Here reason ends and revelation begins. Nor has any of the philosophers been able to come back from the grave to tell us whether their fine arguments were born out by the actual article of death itself.
The scientist comes. He says, “I’m sorry, my friend. I did my best. I trained your doctor and equipped your hospital. I provided you with the best of medicines. But I have failed. Nor can any scientist tell me how to bring you back to life, despite all that we know about cells, genes, chromosomes, and DNA. We have removed your name from our list of patients. We have failed you at the last.”
The family comes. There stands the weeping mother and the brokenhearted father. He cries like David, “Oh, my son, my son! Would God that I had died for you, my son, my son!”
For those who are outside of Christ, death is final, cold, cruel, callous, and utterly uncaring. It is ugly, menacing, and inescapable. Paul calls it “the last enemy.” When he arrives, it’s all over.
The only consolation we have is in the Word of God. We have God’s Word for it, that for the believer all is well. “Ye sorrow not,” Paul says, “even as others which have no hope.”
Indeed, he deliberately describes death as sleep. We actually court sleep.
We sorrow! But we have God’s Word for it, that our loved ones are only asleep—a reference to the state of the body. The soul does not sleep; the body does. The soul is made of the same stuff as eternity. It never gets tired, never gets old, never gets ill, and never sleeps. The body of the departed believer is asleep. Jesus said the same thing of Lazarus and declared His intention of going to Bethany to awaken him (John 11:1–15).
Outside of divine revelation, we have no word to comfort us when death strikes.
 Phillips, J. (2009). Exploring 1 & 2 Thessalonians: An Expository Commentary (1 Th 4:13–15). Kregel Publications; WORDsearch Corp.