Having a fit of rage is not the same as righteous indignation. When you have a fit of rage, you are angry for no legitimate reason. When you express righteous indignation, you are angry for a legitimate reason that relates to the kingdom of God.
God prefers that you remain calm and peaceful at all times. However, he understands that there are times when you will indeed express righteous indignation. When you do, be certain that you do not sin, or become filled with hate.
The Lord God Almighty El Shaddai