On the basis of these observations, I would like to make the following assumption. I will assume that we receive our emotions as gifts from God, and that each of them has been given to us for our well being. For example, the presence of the emotion of fear is necessary or we would be falling off of bridges, petting wild animals, and walking into trucks. Fear lets us know what to avoid so that we don't injure ourselves. Anger stops other persons form using us for purposes other than what God intended.
Anger is also an important source of energy for solving interpersonal problems.
We are told to be angry but to sin not. . Returning to other examples of how our emotions contribute to our well being, the emotion of shame keeps us from being gross, or from treating unfamiliar situations or persons as if they were familiar. Guilt lets us know we have standards and that our beliefs and behaviors are inconsistent with each other, and that we need to change one or the other of them. Regret lets us know that next time we want to do something different. If we were incapable of feeling regret, we could not learn from our experiences, and we would keep making the same mistakes over and over.