Didn't apply logic or interpretation just showed the verses. Enlarged those words which you missed. How about checking it out in another translation. What is written, is what I read, and is what I believe.
John 11:11-15 New International Version (NIV)
After he had said this, he went on to tell them,
“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 his 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, so that you may believe. But let us go to him.”
See those enlarged words, why the heck should I interpret those, if that is what the Lord Jesus said.