19 My dear brothers and sisters, take note of this: Everyone should be quick to listen, slow to speak and slow to become angry, 20 because human anger does not produce the righteousness that God desires.
Once again James sounds very similar to the book of Proverbs in discussing speech and dealing with anger. The order that James lists listening, speaking, and anger are important. Each idea builds upon the next one. A person who is focused on listening will have to be slow to speak as they must take the time to comprehend what is said before speaking. Those who are slow to speak will be much less likely to be involved in arguments as their words will be carefully chosen.
One of the biggest causes of anger is communication or specifically a lack of communication. Certainly people will do and say things that will anger us from time to time. Overall though, most people are not out to intentionally make us angry. We become angry because we think that something was said when it was not. Or maybe the words we heard were correct but the intention of those words was misinterpreted. Flying off the handle in an angry retort is unlikely to make such a situation better. But if thought is given to a response, a case of miscommunication can easily be resolved.
James is not finished discussing what comes out of one’s mouth. He will later expound upon the tongue more in chapter 3.