It is recorded by Muhy al-Din ibn al-'Arabi, author of al-Futuhat al-Makkiya (The Makkan Conquests), that during the early centuries of Islam, righteous people would either write down or memorize their daily actions, thoughts, and words, and then analyze and criticize themselves for any evil or sin they had committed. They did this to protect themselves from the storms of vanity and the whirls of self-pride. They would ask God's forgiveness after this self-analysis, and would repent sincerely so that they might be protected against future error and deviation. Then they would prostrate in thankfulness to God for the meritorious deeds or words that the Almighty had created through them.
Self-criticism may also be described as seeking and discovering one's inner and spiritual depth, and exerting the necessary spiritual and intellectual effort to acquire true human values and to develop the sentiments that encourage and nourish them. This is how one distinguishes between good and bad, beneficial and harmful, and how one maintains an upright heart. Furthermore, it enables a believer to evaluate the present and prepare for the future. Again, self-criticism enables a believer to make amends for past mistakes and be absolved in the sight of God, for it provides a constant realization of self-renewal in one's inner world. Such a condition enables one to achieve a steady relationship with God, for this relationship depends on a believer's ability to live a spiritual life and remain aware of what takes place in his or her inner world. Success results in the preservation of one's celestial nature as a true human being, as well as the continual regeneration of one's inner senses and feelings.
A believer, in his or her spiritual and daily life, cannot be indifferent to self-criticism. On the one hand, he or she tries to revive his or her ruined past with the breezes of hope and mercy blown by such Divine calls as: Repent to God (24:31) and: Turn to Your Lord repentant (39:54), which come from the worlds beyond and echo in his or her conscience. On the other hand, warnings as frightening as thunderbolts and as exhilarating as mercy are contained in such verses as: O you who believe! Fear God and observe your duty to Him. And let every soul consider what it has prepared for the morrow (59:18) bring the believer to his or her senses and make one alert once again (against committing new sins). In such a condition, a believer is defended against all kinds of evil, as if enclosed behind locked doors.
Taking each moment of life to be a time of germination in spring, a believer seeks ever-greater depth in his or her spirit and heart with insight and consciousness arising from belief. Even if a believer is sometimes pulled down by the carnal dimension of his or her being and falters, he or she is always on the alert, as is stated in: Those who fear God and observe His commandments, when a passing stroke from Satan troubles them, they immediately remember (God), and lo! they are all aware (7:201).
Self-criticism resembles a lamp in the heart of a believer, a warner and a well-wishing adviser in his or her conscience. Every believer uses it to distinguish what is good and evil, beautiful and ugly, pleasing and displeasing to God. Through the guidance of this well-wishing adviser, the believer surmounts all obstacles, however seemingly insurmountable, and reaches the desired destination.
Self-criticism attracts Divine mercy and favor, which enables one to go deeper in belief and servanthood, to succeed in practicing Islam, and to attain nearness to God and eternal happiness. It also prevents one from falling into despair, which will ultimately lead to reliance on personal acts of worship to be saved from Divine punishment in the Hereafter. 
As self-criticism opens the door to spiritual peace and tranquillity, it also causes one to fear God and His punishment. In the hearts of those who constantly criticize themselves and call themselves to account for their deeds, this Prophetic warning is always echoed: If you knew what I know, you would laugh little but weep a lot.  Self-criticism, which gives rise to both peacefulness and fear in one's heart, continuously inspires anxiety in the hearts of those who are fully aware of the heavy responsibility they feel the anxiety voiced as in: If only I had been a tree cut into pieces. 
Self-criticism causes the believer to always feel the distress and strain expressed in: Earth seemed constrained to them for all its vastness, and their own souls straitened to them (9:118). The verse: Whether you make known what is in your souls or hide it, God will bring you to account for it (2:284) resounds in every cell of their brains, and they groan with utterances like: I wish my mother had not given birth to me! 
While it is difficult for everyone to achieve this degree of self-criticism, it is also difficult for those who do not do so [to be sure that they will be able] to live today better than yesterday, and tomorrow better than today. Those who are crushed between the wheels of time, whose present day is not better than the preceding one, cannot perform well their duties pertaining to the afterlife.
Constant self-criticism and self-reprimand show the perfection of one's belief. Everyone who has planned his or her life to reach the horizon of a perfect, universal human being is conscious of this life and spends every moment of it struggling with himself or herself. Such a person demands a password or a visa from whatever occurs to his or her heart and mind. Self-control against the temptations of Satan or the excitement of temper are practiced, and words and actions are carefully watched. Self-criticism is constant, even for those acts that seem most sensible and acceptable. Evening reviews of words and actions during the day are the rule, as are morning resolutions to avoid sins. A believer knits the "lace of his or her life" with the "threads" of self-criticism and self-accusation. 
So long as a believer shows such loyalty and faithfulness to the Lord and lives in such humility, the doors of heaven will be thrown open and an invitation will be extended: Come, O faithful one. You have intimacy with Us. This is the station of intimacy. We have found you a faithful one. Every day he or she is honored with a new, heavenly journey in the spirit. It is God Himself Who swears by such a purified soul in: Nay, I swear by the self-accusing soul! (75:2).
 Al-Bukhari, "Kusuf," 2; Muslim, "Salat," 112; Abu 'Isa Muhammad ibn 'Isa al-Tirmidhi, "Kusuf," in Sunan, 4 vols. (Beirut, n.d.), 2.
 Al-Tirmidhi, "Zuhd," 9; Muhammad ibn Yazid al-Qazwini Ibn Maja, "Zuhd," in Sunan, 2 vols. (Egypt, 1952), 19.
 Muhammad Ibn Sa'd, Al Tabaqat al-Kubra, 8 vols. (Beirut, 1980), 3:360.
 7 In other words, all moments of one's life are spent in self-criticism and con-stant awareness of what one says and does.