“Of all the feelings that man’s heart experiences, there is none perhaps which so soon runs into sin as the feeling of anger. There is none which once excited seems less under control. There is none which leads on to so much evil. The length to which ill-temper, irritability, and passion, will carry even godly men, all must know. The history of ‘the contention’ of Paul and Barnabas at Antioch, and the story of Moses being provoked till he ‘spake unadvisedly with his lips,’ are familiar to every Bible reader. The awful fact that passionate words are a breach of the sixth commandment, is plainly taught in the Sermon on the Mount. And yet here we see that there is an anger which is lawful.
“Let us leave this subject with an earnest prayer, that we may all be enabled to take heed to our spirit in the matter of anger. We may rest assured that there is no human feeling which needs so much cautious guarding as this. A sinless wrath is a very rare thing. The wrath of man is seldom for the glory of God. In ever case a righteous indignation should be mingled with grief and sorrow for those who cause it, even as it was in the case of our Lord. And this, at all events, we may be sure of, — it is better never to be angry, than to be angry and sin.”
– J. C. Ryle, Expository Thoughts on Mark (Banner of Truth, 1985; first published 1857), 47-48