Wa`alykum As-Salaamu Warahmatullahi Wabarakaatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear questioner, may Allah reward you abundantly for your interest in knowing the teachings of your religion, Islam!
As regards your question, we’d like to cite for you the following:
“Tazkiyat an-Nafs is the basis for development and improvement of the personality. It is a long, pro-active, and uphill task. It is not an easy esoteric rite or overnight formula. Misunderstanding of Tazkiyah manifests when people look for quick methods of becoming better. Some may visit graves of the righteous; some may repeat certain supplications for a given number of times. Yet others subject themselves to physical suffering in the hope that this will lead to spiritual purity. All of these are forms of escapism from facing the real challenges of Tazkiyah.
Tazkiyah is by Allah
Allah purifies whom He wants (4:49). All human effort at Tazkiyah should always be accompanied by supplication for Allah's intervention without which human effort will bear no fruit. On the other hand, it is wrong for a human to make no effort and passively expect Allah to intervene. Humans must play their role before expecting Allah's help.
Human Efforts Toward Tazkiyah
The human can do a lot to refine the soul (Nafs). The Qur'an talks about humans who purified themselves and about human efforts toward refinement (35:18). Humans have been described by the Qur'an as clean (19:19). Some human self-refinement, Tazkiyah, involves: correct and firm `Aqidah, fulfillment of acts of worship, avoiding the forbidden, generally being conscious of the Creator, and constant meditation about the creation. This is followed by personal development and improvement, which consist of a good character and behavior; assertiveness, and self-confidence. An individual may not succeed alone. Living in a righteous community surrounded by others is necessary to motivate and encourage refinement. Islam is a practical religion. Achievement of purity is through action. Good behavior, avoiding bad behavior, and being strong and assertive in making correct choices is the practical way to purity.
Preliminaries of Tazkiyah
Good intentions: Tazkiyah is not accidental. It is a pro-active process. It must be based on the good and sincere intention to please Allah and draw near to Him. The process of Tazkiyah can not be sustained if done for other reasons.
Commitment: Tazkiyah can be a difficult process especially at the start. Some may try and think of giving up. Continuing commitment is needed to be able to travel all the way to the end of the process.
Being true: The person undertaking Tazkiyah must be true to self, to others and to Allah. True to self means understanding and accepting yourself as you are with all the negatives and positives such that the negatives can be suppressed while the positives can be enhanced. Being true to others is saying and acting according to the truth and never deceiving or giving the wrong impressions.
Earnest entreaty to Allah: Tazkiyah requires that a very strong desire and longing to turn to Allah and get closer to Him. This gives a sense of direction and a sense of purpose to the Tazkiyah efforts.
Tazkiyah at the Conceptual Level
Answering the call of Allah: The path of virtue is the straight path. Humans must stick to the straight path. Sticking to the straight path has a lot of virtues (41:30-32). Those who stick to the path of virtue are answering the call of Allah (8:24). The misguided ignore this call or turn away from it. They end up following the wrong paths that lead them to perdition.
Renouncing materialism (Zuhd): Zuhd means giving priority to the after life. Preferring the material world is severely condemned by the Qur’an. The Hereafter is better than the material world (3:14-15). Zuhd has been misunderstood by many down the centuries. It does not mean withdrawal from life and making no contribution to the building of a material civilization. Neither does it mean refusing to enjoy the bounties that Allah put on earth for the benefit of humans. Living like a hermit may not be the total or only meaning of Zuhd. Zuhd means belittling materialism and having a correct relation to material goods as things to be used by humans in the fulfillment of their duties to Allah and not as masters who control human behavior.
A person may own a lot of money and material goods but he knows that in front of Allah they are worth very little. He will not be intoxicated by nor worship material goods. He will have a higher scale of values that he refers to. His maximum pleasure will not be attained by material possessions. Zuhd also means not selling eternal values for the sake of temporary material advantage on earth; such a trade is indeed a losing trade. A human should live on earth as a stranger or a traveler in the knowledge that the life in the Hereafter is eternal and that all the time spent on earth should be used to prepare for the Hereafter.
Vigilance against Satan: Satan is an enemy of humans. A human who wants to stay pure must be vigilant against Satan's influence. Satan has limited influence over human action. He causes waswasah (Satanic whispers). He leads astray. Satan is never away from humans. Every human has a Satan around him or her. The Prophet, peace and blessings be upon him, in a very revealing metaphor said that Satan circulates in the human body as does the blood. Satan will always try to confuse humans. He, for example, will attempt to prevent the human from waking up in the morning to pray. The human is however not helpless against Satan. There are many simple actions that will chase Satan away and all of these are part of the process of Tazkiyah. The sound of Adhan makes the Satan run away. Reading thr Qur'an also chases away Satan. Thus a human who is regular in prayer and recites the Qur'an often as a guide to life will be vigilant against the machinations of Satan."
Excerpted, with modifications, from: