I like G. B. Caird and I think his synopsis of the evil in the world is spot on. This quote come from his commentary on Revelation, specifically his discussion of the locusts of chapter nine and their human-like faces (p. 120). He writes
Evil may take many sinister forms and ramify far beyond the immediate implications of individual sin; but in the last analysis it has a human face, for it is caused by the rebellion of human wills against the will of God.
Αυτω η δοξα