Anger tells us to face a threat
Anger alerts us to a threat. That makes anger and fear closely related. Instead of flight, though, anger motivates us to move against the threat. We can become angry when we lose someone or something we love. We may experience the loss as a sort of robbery. We can be angry with God, with someone who was reckless, or with the person who died. Anger urges us to act against an injustice when one has actually occurred.
                                                           
The risk of anger is rage. Rage is blind aggression unleashed against a threat. Rage, of course, is dangerous because of its explicit mindless intent to harm and destroy.

For a more in-depth examination of anger, you can take my free online FireWorks: Anger Management in Adult-Child Relationships course.