John Cassian, Conferences I–X VI.5: An objection, how God Himself can be said to create evil

Germanus: We often read in holy Scripture that God has created evil or brought it upon men, as is this passage: “There is none beside Me. I am the Lord, and there is none else: I form the light and create darkness, I make peace, and create evil.” And again: “Shall there be evil in a city which the Lord hath not done?”