As you develop better boundaries, you have less need for anger. This is because in many cases, anger was the only boundary you had. Once you have your no intact, you no longer need the “rage signal.” You can see evil coming your way and prevent it from harming you by your boundaries.
Don’t fear the rage you discover when you first begin your boundary development. It is the protest of earlier parts of your soul. Those parts need to be unveiled, understood, and loved by God and people. And then you need to take responsibility for healing them and developing better boundaries.
This brings us to an important point about anger: The more biblical our boundaries are, the less anger we experience! Individuals with mature boundaries are the least angry people in the world. While those who are just beginning boundary work see their anger increase, this passes as boundaries grow and develop.
Why is this? Remember the “early warning system” function of anger. We feel it when we are violated. If you can prevent boundary violation in the first place, you don’t need the anger. You are more in control of your life and values.
— Dr. Henry Cloud & Dr. John Townsend, Boundaries, p. 114-115