Anger has been created to dispel harm. If there were no anger, then how could we dispel that which was harmful to us?
Like a sword whose job it is to cut. On whosever throat you place the sword, it will cut. It is the choice of the sword wielder to use the sword on a fit occasion. Similarly using anger when it is not appropriate is also bad. There is indeed difficulty in controlling anger but later on there is a certain special pleasure as well.
If one doesn’t control anger and says whatever one wants to say, then the Self (Nafs), but later on there develops a certain grime in the heart and then regret. Peace and solace become nonexistent. The same Self, which was inciting you earlier, now reproaches you. After this, on seeing the results of the anger, one feels really sorrowful. That is why, use anger appropriately. This was what the Companions (May Allah be well pleased with them) did.
When anger takes root in the heart, then it creates many (spiritual) diseases like enmity, jealousy, rancor, etc. It is as if anger is a seed which leads to many evils. It is due to anger only that one curses oneself and one’s children. Divorces happen and homes are shattered and people commit suicide and this anger goads people into committing murders as well. That’s why dispelling anger is highly necessary. If there is cheap stuff in the house, then ordinary locks are used and if there is expensive stuff, strong locks are used and if there is a treasure in the house, a lot of locks are placed and a guard is also set. In the same way, considering its importance, special preparations are needed to control anger as well.
Remember that a Muslim gains the status of a worshipper and ascetic by being calm and composed. Hadhrat Imam Ja’afar Saadiq (May Allah be well pleased with him) said: The root of every evil is anger and one’s forbearance is tested in times of anger.
Hadhrat ‘Abdullah bin ‘Umar (May Allah be well pleased with him) asked the Holy Prophet (Sallallahu alaihi wa sallam): What can save me from the wrath of Allah Most High? The Holy Prophet (Sallallahu alaihi wa sallam) said: You stop being angry at others and Almighty Allah will not be angry with you.