Be angry but do not sin; do not let the sun down in your anger...Ephesians 4:26

Be angry if you must, there is justification in anger sometimes. Some criticisms, some reprimands bring in education, fresh insight. It opens up closed minds for the learning, the awakening,  and the refining. 

For the anger which arises from human emotions, the passion of the moment and the circumstance, before the sun goes down and you slumber, make peace, lest your anger builds up and the warring spills over into the new day. Make peace, make up before the day is done and then you will arise renewed without a burden in your heart and mind! Ah! how  peaceful and beautiful the new day will be!