Consider an argument from the less to the greater. In the human sphere he who loves purity and chastity and has no wrath against impurity and unchastity is a moral leper. He who pities the poor and defenseless and has no wrath against the oppressor who crushes the weak and slays the defenseless, but loves them too, is a fiend. Divine wrath is Divine Holiness in activity. Because God is holy He hates sin, and because He hates sin His anger burns against the sinner.