John Cassian, The Institutes VIII.2: Of those who say that anger is not injurious, if we are angry with those who do wrong, since God Himself is said to be angry

Of those who say that anger is not injurious, if we are angry with those who do wrong, since God Himself is said to be angry.

We have heard some people trying to excuse this most pernicious disease of the soul, in such a way as to endeavour to extenuate it by a rather shocking way of interpreting Scripture: as they say that it is not injurious if we are angry with the brethren who do wrong, since, say they, God Himself is said to rage and to be angry with those who either will not know Him, or, knowing Him, spurn Him, as here: “And the anger of the Lord was kindled against His people;” or where the prophet prays and says, “O Lord, rebuke me not in thine anger, neither chasten me in thy displeasure;” not understanding that, while they want to open to men an excuse for a most pestilent sin, they are ascribing to the Divine Infinity and Fountain of all purity a taint of human passion.