Even if some illness or loss comes upon a person through natural means, he should believe with perfect faith that, in fact, it was his sins that brought it upon him. Our Sages therefore said: “If a man sees that painful sufferings visit him, let him examine his deeds” (Berachos 5a). I have heard about a certain individual—a man of good deeds, being God-fearing and vigilant of evil—who had this custom: whenever he suffered any loss in his business or any other type of loss, he would immediately return home from the marketplace and confess to Hashem and cry, saying, “My sins have caused this!”
But nowadays, because of our sins, people search for the “natural” causes; “This illness is a result of such-and-such,” and, “This loss is a result of cause x and y,” and they do not give any thought to examining their ways and repenting. The commentators have pointed out that the word הַטֶבַע (“the Nature”) and אֱ-לֹהִים (“God”) share the same numerical value: 86. This is to teach that all of nature is in truth a manifestation of God’s Providence.
How good it would be for one to make this his practice: Whenever he sees that some suffering has come upon him, he should accept upon himself with full force to desist from some negative behavior to which he had been accustomed, and to begin keeping some positive behavior that he had not been keeping. By doing so, he will find favor to Hashem like one who has brought an offering.