It is impious to say that evil has its origin from God, because naught contrary is produced by the contrary. Life does not generate death, nor is darkness the beginning of light, nor is disease the maker of health, but in the changes of conditions there are transitions from one condition to the contrary.

Exegetic Homilies (The Fathers of the Church, Volume 46) (ed. CUA Press, 2010) - ISBN: 9780813211466