Tazkiyah, a continuous process, goes on day in and day out. When it does not happen in this way, there is a Hadith which describes the result of this: “The heart becomes covered with rust, just like iron when it comes in contact with water.” A question was asked: “O Prophet! What is the way to purify or clean one’s heart?” The Prophet replied, “Remembering death often and studying the Quran.” (Shu’ab-ul-Iman, Hadith No. 1859)

This tradition of the Prophet tells us of a psychological reality. That is, in the context of the society he lives in, man has repeatedly to undergo such experiences as produce negative feelings within him, for instance, anger, hatred, violence, revenge, etc. Man ought to bury these feelings instantly, for, if he fails to do so, they will become a permanent presence in the human mind, and a time will come when it will be almost impossible to eliminate them.

There are two major parts of the human mind, the conscious and the unconscious. It is quite natural for negative feelings to first of all enter the conscious part of the mind. If such feelings are not immediately cast out from the mind, they gradually reach the unconscious part of the mind, from where it becomes difficult to eradicate them. Man should always remain vigilant about this. At all times he should keep converting his negativity into positivity. That is, he must de-condition his conditioned mind in order to purify it and keep it free from pollution. The only way of purification, or de-conditioning, is to repeatedly remind himself of death and to reflect on the purpose of life in the light of the Quran.

Source: The Purpose of Creation