Anger is one of those sins which we tend to justify in ourselves. They made me do it - is our basic response, whether it is the unreasonable demands of the boss, or the unwilling response of an employee, or the perceived thoughtlessness of a spouse, or the continual 'Why?' of a child.
How do we deal with anger? Our reactions under pressure give us a helpful gauge of our hearts - whilst it may not be explosive anger which is obvious to everyone. It can be an internal sigh, a growing sense of frustration, or a deepening sense of bitterness. Anger is sin, 'Ah but what about righteous anger?' we quickly say. I think if we look at our hearts we have to say we very rarely are righteously angry, most often our anger is prompted by our pride, or a sense of our rights being infringed, or just plain selfishness.
We need to call sin sin. Whilst we try to justify it or excuse it we will never confront it, see the need for change or repent of it.
It is impossible for us not to the be in situations which may cause us to respond with anger, but everyone of those situations is a God given opportunity for me to nail my sin to the cross once again. Sin is not my master I am to walk in the Spirit, that means anger is not my master, I am not incapable of responding differently, anger is no longer my default response.
But in order for that reality to bite we need to learn to talk to ourselves and correcting ourselves. When I am in a situation where I find myself responding with anger I need to tell myself over and over again that Christ has died to free me from the hold of anger, when I find myself rehearsing past wrongs I am to tell myself that I am a great sinner called to live and relate to others by grace and to forgive their little sins (that is a perspective we need to keep hold of - no matter what is done to us it is a tiny wrong compared to our assault on God's glory).