إِنَّ الَّذِي فَرَضَ عَلَيْكَ الْقُرْآنَ لَرَادُّكَ إِلَىٰ مَعَادٍ
Surely, the Prayer restrains from all that is indecent and shameful, and all that is evil. (Al-‘Ankabūt 29:45)
Although people perform the Prayer, and the Prayer restrains them from all that are indecent and evil, it is always possible that they can make some errors. The following hadīth of Prophet Muhammad, upon him be peace and blessings, is quite significant to express this reality: “All human beings commit errors, and the best of those who commit errors are those who repent.”
If people perform the Prayer perfectly, the luminous periods of time in their lives expand widely while their dark and obscure periods of time narrow. Their spiritual expansion increases, occurs more frequently and lasts longer while their distressful moments almost disappear. The openings that give way to carnality and devilishness in their inner world become narrow while the doors opening unto spirituality and angelic nature and manners become wide open. However, all of these are dependent upon the performance of the Prayer consciously and with a vigilant heart and boiling feelings. Therefore, the Prayer described in the verse above is the Prayer performed perfectly. It is inevitable for those who cannot achieve such state of mind during the Prayer to commit errors.
A Prayer’s restraining people from indecencies and evils and urging them good and virtues is also dependent on a serious concentration during it. For instance, at the moment of the breaking the fast of Ramadan after a long, hot day of summer, we feel the water we drink in each cell of our bodies. Like this, we should feel every word that we recite and every act that we do during the Prayer in our consciences in the same fashion. Every word and every act of the Prayer should generate a shiver within us and remind us that we are in the presence of God so that the Prayer can restrain us from indecencies and evils. Thus, we can say that we can be far from evil to the extent of the level or degree of spirituality and consciousness that we acquire through the Prayer. In other words, the profundity in performing the Prayer can in time become an important factor in determining our behavior.
Off the topic, I should note the following point: people should always question themselves about the soundness of their way of living and worship, provided that they do not lose their determination and fall into despair. They should always worry if their Prayers and other devotions will be refused in the Hereafter. Yet, they should worry only for their own selves and refrain from thinking ill of others. Ill-suspicion of others without any substantiated proof is forbidden by Islam. It is useful here to repeat a truth: a person should act like a public prosecutor and plaintiff in their own name and like a lawyer in the name of others. A person should see even their minor faults as dangerous as snakes on their own behalf, but they should forgive and be compassionate like a mother with respect to even the biggest errors of others. While warning others because of their wrong, they should speak sincerely and purely for the sake of the reform of their addressee. This is the manner and style of the Qur’ān, and God Almighty calls us to follow the guidance of the Qur’ān in all of our thoughts and behavior, as follows: “Recite and convey to them what is revealed to you of the Book, and establish the Prayer in conformity with its conditions” (Al-‘Ankabūt 29:45).
Back to the topic, so long as the Prayer is performed purely with the intention of fulfilling an important order of God and pleasing Him and as long as it is performed regularly without missing any time, then the Prayer will definitely prevent one from committing evils and indecencies sooner or later. A Prayer which prevents one from evils and indecencies will certainly keep one from association of partners with God and other types of misguidance and the errors and sins that lead to them. For the Prayer is the kind of worship composed of verbal and active remembrance, glorification, praise, and exaltation of God. It is the greatest of the acts or types of worship, as stated in the verse: “Surely God’s remembrance is the greatest (of all types of worship). God knows all that you do” (Al-‘Ankabūt 29:45).
 Tirmidhī, Qiyāmah, 49; Ibn Mājah, Zuhd, 30; Dārimī, Riqāq, 18.