Mourning is a…

Mourning, according to God, is sadness of soul, and the disposition of a sorrowing heart, which ever madly seeks that for which it thirsts; and when it fails in its quest, it painfully pursues it, and follows in its wake grievously lamenting.
–Saint John Climacus (c. 525-606)

Through sickness…

When you see your body wasted through sickness, do not murmur against God, but say: “The Lord gave, and the Lord hath taken away; blessed be the name of the Lord.” You are accustomed to look upon your body as upon your own inalienable property, but that is quite wrong, because your body is God’s edifice.
— Saint John of Kronstadt (1829-1908)