Hazrat Abu Huraira narrates that a person came to the Prophet Muhammad and said that please give some advice but dont make the advice too long. Meaning that that person not only asked for advice but also gave a condition that it has to be short too. Hazrat Muhammad (صلی اللہ علیہ وسلم) did not show any expression of displeasure and instead said that 'never get angry'. If a person follows this advice then a lot of his sins will be reduced.
Two origins of sin; anger and following your desires:
This is because if a person pays attention, then he would notice that almost always the feelings of anger and desires cloud our judgment so that we make decisions that lead to regrets. Following your desires actually means following your animal instincts which is known as 'shaywat' in Arabic. Along with this letting anger guide you also lead to bad decisions.
Anger is a natural emotion:
Although anger is an inbuilt emotion, controlling it is vital which an effective method to counter negative forces is indeed. Sins that originate from anger: if not controlled, then Anger can become the source of envy, arrogance, hatred, and animosity. For instance if a person gets furious then this can result in his being rude or insulting to the other person or beating him too which obviously are major sins. Killing someone without reason is a sin of great magnitude. Hazrat Muhammad's Hadith also tells us that cursing someone is highly discouraged and is undesirable, and killing someone forces the killer out of the circle of Islam. (Bukhari)
Hurting someone emotionally is also a great sin that can be brought about by anger.
Hatred is often caused by anger too: this is most evident when your anger is directed at someone who is above you in terms of ranking i.e. your boss for instance. Since one cannot express the anger directly, hatred for the other person is initiated.
Jealousy is also caused by anger: anger at someone leads to jealousy at the other person's happiness too. This further fuels the fire of your animosity resulting in more and more sins. Related to this, verse 134 of Surah Al-Imran tells us that virtuous Muslims are those that don't let their anger guide them and instead forgive others.
Why anger is so bad for you?
As you already know that Hazrat Muhammad (صلی اللہ علیہ وسلم) discouraged us from giving free rein to our anger. He told us that it’s a trick of shaitan. Hazrat Muhammad ordered us that if we are standing and anger over powers us then we should sit, if we are sitting then we should lie down and if still your anger isn't lessened then drink water. Today experts in medicine tell us that anger is a factor in diminishing our strength. Also elderly ladies used to discourage women from breastfeeding when they are angry because this was dangerous for the baby and the anger was transferred to the baby too. A scientist in America Reed Forbi Williams says that those hold on to emotions such as anger, hatred and animosity die earlier; anger effects us in the same manner as smoking and high blood pressure. Intense anger and hatred leads to the weakening of the heart and those people who are highly dejected about their life and have many wants and desires also end up with many illnesses. Contrary to these, people who are high on the emotion of gratitude and are optimistic as well as control their wants instead of letting their wants go uncontrolled fare far better in life.
Conclusively, keeping this all this in mind it seems quite important that one exercises control over their anger using the Prophet Muhammad's Hadith about sitting, lying down or drinking water if anger is too strong.
