"How wonderful is the affair of a believer! For his entire affair is good, and this applies only to a believer. When good befalls him, he is thankful and thus, it is good for him, and when evil befalls him, he is patient and thus, it is [also] good for him. And that is for the believer alone."
— The Messenger of Allaah [sallAllaahu `alayhi wa sallam], reported by Muslim in his Saheeh [4/2295 no.2999] from Suhayb [radiAllaahu `anhu].