So many in the world today are angry, and understandably so. There are a great many injustices not to mention heated disagreements over how to overcome them. Anger is not inherently bad. It's a useful emotion that alerts us when something is wrong, particularly when something could be a potential threat. It spurs us to take action. However, once we recognize that something must be done and are determined to take action, anger ceases to be as useful, except perhaps as a motivating force to keep striving when obstacles arise (though even then there are arguably much more powerful motivators for that purpose). While anger can cause us to take action, it doesn't help us to think rationally in order to determine what that action should be.
There are those who try to justify feelings and acts of hatred and even violence and even go so far as to use scripture to defend themselves. One of the most notable examples is the story of Jesus chasing the money lenders from the temple (see John 2:14-17). It seems clear that he was angered or at least indignant because of the way in which they had desecrated His Father's house. However, it should be remembered that Jesus was not like mortal men and women. He always demonstrated a prodigious level of control over His actions. How many of us can say the same? Noble as our intentions may be, our pride has a way of hampering our judgement and causing us to forget the things Jesus actually taught about how to treat those who have wronged us (see Luke 6:27, Mark 11:25, etc.).
We don't have to be ashamed of our anger. We just need to remember not to let it rule us.