The fact that those who come to this world continuously depart, and the young grow old, and man perpetually revolves amid death and separation testifies that he did not come to this world to enjoy himself and receive pleasure.
Moreover, while man is the most perfect, the most elevated, of living beings and the best endowed in regard to members and faculties, he dwells on past pleasures and future pains, and so passes a grievous, troublesome life, lower than the animals. This means that man did not come to this world to live in a fine manner and pass his life in ease and pleasure. Rather, he possesses vast capital, and he came here to work and do trade for an eternal, everlasting life.
The capital given to man is his lifetime. Had there been no illness, good health and well-being would have caused heedlessness, for they show the world to be pleasant and make the hereafter forgotten. They do not want death and the grave to be thought of; they cause the capital of life to be wasted on trifles. Whereas illness suddenly opens the eyes, it says to the body: “You are not immortal. You have not been left to your own devices. You have a duty. Give up your pride, think of the One who created you. Know that you will enter the grave, so prepare yourself for it!” From this point of view, illness is an admonishing guide and adviser that never deceives. It should not be complained about in this respect, indeed, should be thanked for. And if it is not too severe, patience should be sought to endure it.