11 Having spoken these things He said to them: “Lazarus, our friend, has fallen asleep; but I am going so that I might wake him up.”
Those of us who have or have had pet animals may have experienced having to make the terrible decision of when to put them down. We know that this is commonly called: ‘putting them to sleep’. We all know it is a decision to cause the animal to die, and none of us looks forward to that dreadful moment.
Jesus used the same kind of expression when he was talking about Lazarus. The term fallen asleep had the double meaning of a) natural sleep or b) the sleep of death. It was in the latter sense that Jesus was talking, since there would have been no reason for Jesus to go and wake Lazarus from a natural sleep.
Paul uses the same expression in his letter to the Thessalonians: And now, brothers and sisters, I want you to know what will happen to the Christians who have died (fallen asleep) so you will not be full of sorrow like people who have no hope – 1 Thessalonians 4.13 (NLT).
The same word is used in Matthew 27.52b-5a, at the moment Jesus died: The earth shook, rocks split apart,  and tombs opened. The bodies of many godly men and women who had died (had fallen asleep) were raised from the dead  after Jesus’ resurrection – (NLT).
Apparently the term ‘sleep’ has been used to signify death since the times of Homer, a Greek writer and poet who is thought to have lived a few hundred years before Jesus.
By using the term sleep to express death, Jesus was gently leading His disciples to come to terms with the death of their friend (he was not just the friend of Jesus). The word ‘friend’ is the same word that is used in verse three, which is translated ‘love’: Then the sisters sent to Him saying: “Lord, the one whom You love (who is your friend) is ill.”
Jesus calls us His friends, and as our friend He will call us out of the sleep of death so that we will live with Him for all eternity.
However, right now He calls us out of the sleep of death that we were in through our sin and disobedience. Now we live in the new life that He has awakened us to.