When he heard this, Jesus said, "This sickness will not end in death. No, it is for God's glory so that God's Son may be glorified through it."
Jesus knew that Lazarus' illness and his death would not be the end of this story. We see Jesus wait two more days and then go to Mary and Martha and Lazarus, who is by now in a tomb. Jesus weeps with those who mourn Lazarus' death. Then, Lazarus is called out of the tomb, by Jesus. This miracle is for the benefit of all of those who would see it or will hear about it, finding themselves compelled to follow Jesus, believing in Him. This miracle glorifies God. [I also find verse 35, "Jesus wept" to be especially moving. (Perhaps for further study?)]
Holy Lord, you have blessed us with written accounts in scripture. The death of Lazarus and his healing is one of the most intense pieces of history saved for us. Thank you for this, and for all of the insight it brings. Amen