The website J.C. Ryle Quotes shares the following from a tract Ryle wrote entitled "Christ in the Sick Room".
Sickness is meant...
1. To make us think--to remind us that we have a soul as well as a body--an immortal soul--a soul that will live forever in happiness or in misery--and that if this soul is not saved we had better never have been born.
2. To teach us that there is a world beyond the grave--and that the world we now live in is only a training-place for another dwelling, where there will be no decay, no sorrow, no tears, no misery, and no sin.
3. To make us look at our past lives honestly, fairly, and conscientiously. Am I ready for my great change if I should not get better? Do I repent truly of my sins? Are my sins forgiven and washed away in Christ's blood? Am I prepared to meet God?
4. To make us see the emptiness of the world and its utter inability to satisfy the highest and deepest needs of the soul.
5. To send us to our Bibles. That blessed Book, in the days of health, is too often left on the shelf, becomes the safest place in which to put a bank-note, and is never opened from January to December. But sickness often brings it down from the shelf and throws new light on its pages.
6. To make us pray. Too many, I fear, never pray at all, or they only rattle over a few hurried words morning and evening without thinking what they do. But prayer often becomes a reality when the valley of the shadow of death is in sight.
7. To make us repent and break off our sins. If we will not hear the voice of mercies, God sometimes makes us "hear the rod."
8. To draw us to Christ. Naturally we do not see the full value of that blessed Savior. We secretly imagine that our prayers, good deeds, and sacrament-receiving will save our souls. But when flesh begins to fail, the absolute necessity of a Redeemer, a Mediator, and an Advocate with the Father, stands out before men's eyes like fire, and makes them understand those words, "Simply to Your cross I cling," as they never did before. Sickness has done this for many--they have found Christ in the sick room.
9. To make us feeling and sympathizing towards others. By nature we are all far below our blessed Master's example, who had not only a hand to help all, but a heart to feel for all. None, I suspect, are so unable to sympathize as those who have never had trouble themselves--and none are so able to feel as those who have drunk most deeply the cup of pain and sorrow.
Summary: Beware of fretting, murmuring, complaining, and giving way to an impatient spirit. Regard your sickness as a blessing in disguise - a good and not an evil - a friend and not an enemy. No doubt we should all prefer to learn spiritual lessons in the school of ease and not under the rod. But rest assured that God knows better than we do how to teach us. The light of the last day will show you that there was a meaning and a "need be" in all your bodily ailments. The lessons that we learn on a sick-bed, when we are shut out from the world, are often lessons which we should never learn elsewhere.
(via J.C. Ryle Quotes)