Scripture Journal

Many believe that a righteous individual will never get angry. This is not true. Righteous individuals do get angry. God himself gets angry. The difference is why we get angry, and how we react. The first few words of verse 22 give us the incite. It is only a sin if we are not justified in getting angry. When it says angry without reason, I imagine it is implying that you must have a good reason. A good measure is whether you think God would be angry in the situation.
Now you notice that it says that you are in danger of the judgment. What does that mean? The judgment would indicate God judgment due to sin, however notice that it does not say that we are convicted. Just that we are in danger. Danger indicates a state where you can still come back before you get into any trouble. Thus when we are angry without cause we can still get ourselves under control and avoid sin.
However the next line indicates that if we act rashly on that anger, then we are in danger of hellfire. Once we have acted rashly we have committed the act. Thus the sin has been made, and judgment on that act has been passed. However again the lord indicates danger, or the possibility, of hellfire. There is still a way back through repentance.
Anger is not sinful. Unjust anger, or acting rashly when angry is sinful, and requires repentance. Think about a time when you where angry, can you honestly say that you where justified before god in being angry? Do you think you reacted in a just manner before God?