One is not sinful for one's inner thoughts
29-5-2014 | IslamWeb
Question:
Asalam o Alaikum. I have habit of torturing people in my mind who do bad to me and curse them in mind or sometimes by speaking but in loneliness not infront of people but I can't ask forgiveness from people. What should I do? And what is remedy for aggressive behaviour and agitation.?
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad 
is His slave and messenger.
First of all, you should know that Sharee'ah permits that someone who is wronged seeks restitution from the wrongdoer, provided that one does not exceed the extent of the wrong done against him. So, if a person has not been cursed by someone, he should not curse, because cursing is a very serious matter. Forgiveness is better and entails a great reward as we have already clarified in Fatwa 84351.
On the other hand, a Muslim is not held accountable just for thinking about something unless he acts upon it. The evidence for this is that the Prophet said: “Allaah has forgiven my Ummah for the inner thoughts that they have unless they speak about it or act upon it.” [Al-Bukhari and Muslim]
If someone speaks about it even in secret or when he is alone, he is held accountable.
If you commit an act of aggression against someone, you should pray to Allaah on his behalf. It is not obligatory to ask the forgiveness of someone whom one has wronged regarding the moral rights because of the disadvantage which is likely to occur. It is enough to supplicate for such a person and seek the forgiveness of Allaah for having done so. For more benefit, please refer to Fatwa 88893.
Moreover, you should avoid anger, and remember that it is from the devil. In case you become angry, you should avoid its effects by practicing the matters clarified by Sharee'ah regarding the treatment of anger, which we clarified in Fatwa 86681. In addition to remembering the virtue of pardoning and forgiving, you should try to preoccupy yourself with something beneficial. All this helps in preventing irritation and aggressive behavior.
Allaah Knows best.