A person once wrote a letter to Hazrat Shaikh Moulana Muhammad Zakariyya (rahmatullahi ‘alaih) complaining of the ill-treatment which he received from certain people despite him treating them kindly. After reading the person’s letter, Hazrat Shaikh (rahmatullahi ‘alaih) wrote the following reply:
You wrote to me mentioning that when a person does not fulfill your rights, or repays your kind treatment with ill-conduct, then you experience grief and are hurt over their ill-treatment. This feeling is natural and it is normal for one to feel hurt when someone treats him badly. However, with the grace and favour of Allah Ta‘ala, you should endeavour to adopt the mindset and train yourself to think that the one who fails to fulfill your rights, or repays your kindness with ill-treatment – in reality, he is doing you a favour.
The reason is that had this person repaid your favour with kindness in this world, then you will only receive the kindness that he showed you in this world. However, the reward that you will receive in the Hereafter for his ill-treatment will be a million times better than the kindness you showed him in this world.
It is for this reason that my Akaabir (pious seniors) would often say, and it was their special practice as well, that a person should not worry about how others are treating him. Rather, his constant worry and concern should be, “How am I treating others and dealing with them?”
بدی را بدی سہل باشد جزاء اگر نيک ہستی فاحسن الی من اساء
To repay ill-treatment with ill-treatment is quite easy
If one is truly pious, he will repay ill-treatment with kindness.
(Qutbul Aqtaab Hazrat Shaikhul Hadith Moulana Muhammad Zakariyya (rahmatullahi ‘alaih) pg. 460-461)