This sickness is not unto death, but for the glory of God. John 11:4 (KJV)
But sickness, we must always remember, is no sign that God is displeased with us; no, more, it is generally sent for the good of our souls. It tends to draw our affections away from this world, and to direct them to things above. It sends us to our Bibles, and teaches us to pray better. It helps to prove our faith and patience, and shows us the real value of our hope in Christ. It reminds us that we are not to live always, and tunes and trains our hearts for our great change. Then let us be patient and cheerful when we are laid aside by illness. Let us believe that the Lord Jesus loves us when we are sick no less than when we are well.
Ryle, J. (1857) Expository Thoughts on the Gospels, Monergism Books, pg. 2021