All I can say is that IF anger or rage leads you to “the dark side” then Creator GOD is there multiplied exponentially. Creators rage is manifested in weather events, genocides, fires, wars, earth quakes, great whirlwinds. I work with people remotely on the phone and today I had a person goad and prod me into taking action and then go into “uh huh”, “ohhh” “uh huh” like is was a sensual event for them. I stayed professional. No screaming or cursing at them. I just ended them. But the call left me with a puzzle. What was that? It just occurred to me that Yoda teaches you cannot get angry. In his training of Luke Skywalker it was the control of this emotion, anger/rage, that Yoda saw as Luke’s Achilles heel. And true to the story line Darth Vador taunted Luke Skywalker to give in to his anger. Then enjoyed Luke’s anger saying he can feel the anger growing within Luke. Darth Vador would tell Luke to let go and give in to his anger and join him on “the dark side”. I watched all those movies and waited for the next one. I am influenced by Yodas teaching. This one about rage could not fasten its grip on me because there are times when the body is spent completely exhausted and there is still work to be done something to accomplish then anger can be that driving force that makes you grunt and grind and grit your way through it. In this manner anger is a positive force to fuel you into the finish line. The rage running through is not directed at anybody. It is simply a manifestation of adrenalin.
Even when you are not pushing past human endurance or strength to defeat an enemy anger is normal and natural when you are faced with an injustice or a wrong. It is what you do with the energy billowing up in your soul. Will you use that fervor in a positive way to bring change? Then it is a positive force.
The place I see where anger is sin is in iniquity. Iniquity as used in the Bible is the conscious decision to do harm to another. IF you are wronged and you make a conscious decision to “make them pay” you are committing the sin of iniquity. In fact any time you make a conscious decision to do harm to another, unless in war when defending what you feel is right, then you are committing iniquity.