He told his friends (John 11:11): Our friend Lazarus has fallen asleep; but I am going there to wake him up.
His disciples replied, "Lord, if he sleeps, he will get better." JESUS HAD BEEN SPEAKING OF HIS DEATH, BUT HE DISCIPLES THOUGHT HE MEANT NATURAL SLEEP.
So then he told them plainly, "Lazarus is dead, and for your sake I am glad I was not there."
It is certain from the above that the word SLEEP is used as a euphemism at that time. It is used as such by Jesus and others.
We are told that it means DEATH. It does not mean ACTUAL sleep.
Why is it so certain? After all the disciples didn't seem to be familiar with the term as a euphemism:
Joh 11:11 These were the things he said. Then after this he told them, "Our friend Lazarus has fallen asleep, but I am leaving to wake him up."
Joh 11:12 So the disciples said to him, "Lord, if he has fallen asleep, he will get well."
Joh 11:13 Jesus, however, had been speaking about his death, but they thought that he was speaking about resting or sleeping.
Joh 11:14 Then Jesus told them plainly, "Lazarus has died.
Today if we said "He's in his final resting place", we'd know it was a euphemism. But if someone said "He's asleep", we would think just what the disciples did...well then wake him up!
I think Jesus uses the language he did to draw a clear comparision between sleep and death. Both are states of unconsciousness that are followed by consciousness.
Another thing about the Lazarus story:
Joh 11:23 Jesus saith unto her, Thy brother shall rise again.
Joh 11:24 Martha saith unto him, I know that he shall rise again in the resurrection at the last day.
Martha is under the impression that he won't rise again until the last day. Jesus doesn't disagree. Why doesn't Jesus just say "He's alive and in heaven now." Why doesn't Jesus feel compelled to tell Martha that Lazarus is watching her from above or whatever?