On the authority of Suhaib (may Allaah be pleased with him) he said: The Prophet (sallallaahu alayhi wa sallam) said:

"Amazing is the affair of the believer, verily all of his affairs are good and this is not for no one except the believer. If something of good/happiness befalls him he is grateful and that is good for him. If something of harm befalls him he is patient and that is good for him"

[Saheeh Muslim, #2999]