His permission, therefore, is usually spoken of in the Holy Scripture as His energy and work. Nay, even when He says that God creates evil things, and that there is no evil in a city that the Lord hath not done, he does not mean by these words that the Lord is the cause of evil, but the word 'evil' is used in two ways, with two meanings. For sometimes it means what is evil by nature, and this is the opposite of virtue and the will of God: and sometimes it means that which is evil and oppressive to our sensation, that is to say, afflictions and calamities. Now these are seemingly evil because they are painful, but in reality are good. For to those who understand they became ambassadors of conversion and salvation. The Scripture says that of these God is the Author.
St. John of Damascus, Book IV of Orthodox Faith, Chapter XIX