"No hay mal que por bien no venga".
The English equivalent is "Every cloud has a silver lining". It means that every bad situation has a bright side. That is to say, something good will come out of it.
As in last week's saying, today's is not translated literally. "Mal" in this context means "a bad situation, bad thing". "Bien" means "something good".
Did you know that "good and evil" is translated as "el bien y el mal"?