Who has good and chooses evil must not be distressed at the evil that comes.
Quien bien tiene y mal escoge, del mal que le viene no se enoje.
The source for the proverb is Sancho Panza's Proverbs, and Others which Occur in Don Quixote edited by Ulick Ralph Burke (Google Books). The poster is made with AutoMotivator. The image is by carolynconner at Flickr. Note the near rhyme: escoge - enoje.