What the Bible says about Jesus Christ's Ability to Heal
(From Forerunner Commentary)
With Lazarus' death imminent, Christ's friends were to learn that the wisdom of godly love does not always shield its recipients from suffering, sorrow, and death (John 16:20-22; II Corinthians 7:9-10). Even the personal affection that His friends enjoyed with Him did not persuade Jesus to stray from His responsibility to glorify God in all that He did. So the family had to experience illness and grief.
The gospels do not record the nature of Lazarus' illness, but it was serious enough for his sisters to request Christ's intervention, expecting Him to immediately heal the disease. The ease and simplicity of their message, “Lord, behold, he whom You love is sick” (John 11:3), shows the faith they had in His ability to heal.
Martin G. Collins
The Miracles of Jesus Christ: The Resurrection of Lazarus (Part One)