THE NEW TESTAMENT uses the word “sleep” to refer to a Christians’ death (1 Thess.4). It started with Jesus. When He told Mary & Martha that Lazarus was only asleep, the disciples thought he would get well since he was only asleep, so Jesus told them plainly that Lazarus was dead (John 11). Jesus used the term “sleep” because what happens to a Christian isn’t the same as what happens to the unrepentant sinner who dies.
Jesus told Martha, “I am the resurrection and the life, he who believes in Me, though he may die, he shall live. And whoever lives and believes in Me shall never die” (Jn.11:25). Jesus was referring to spiritual death, which is the separation of consciousness from God. Jesus was saying that anyone who believes in Him will never be separated from God!