The Greatest Jihad:Combat with the Self
Divine Blessings (6)
Someone from whose hands, tongue and eyes other Muslims are not safe is not truly a Muslim, although he may be outwardly and formally a Muslim who has formally proclaimed: "La ildha illalldh " (There is no god but Allah). If, God forbid, you want to offend somebody, to slander them or to backbite, you should know that you are in the presence of the Lord; you are to be the guest of God the Almighty, and in the presence of God, the Supreme, you would behave rudely to one of His servants, and to slander one of the servants of God is to slander God. They are the servants of God, especially if they are the scholars on the path of knowledge and piety [taqwd]. Sometimes you see that because of such affairs man reaches such a state that he denies God at the moment of his death! He denies the divine signs:
"Then evil was the end of those who did evil, because they rejected the signs of Allah and used to mock them" (Q 30:10). These things occur gradually. Today, an incorrect view; tomorrow, a word of backbiting; and the next day, slander against a Muslim, and little by little these sins accumulate in the heart, and make the heart black and prevent man from attaining knowledge [ma 'rifat] of Allah, until it reaches the point that he denies everything and rejects the truth.
According to some ayah of the Qur'an as interpreted through some reports, the deeds of men will be presented to the Prophet (s) and the pure Imams ('a) and will be reviewed by them.29 When the Prophet reviews your deeds and he sees how many errors and sins there are, how upset and distressed will he be? You do not want the Apostle of God to become upset and distressed; you do not want to break his heart and make him sad. When he witnesses that the page of your deeds is replete with backbiting, slander and speaking ill of other Muslims and that all your attention was devoted to this worldly and materialistic affairs and that your heart was overlowing with malice, hatred, spite, and suspicion towards each other, it is possible that in the presence of God, the Supreme and Holy, and the angels of Allah, he will be embarrassed that his community and followers were ungrateful for their divine blessings, and thus unbridled and heedless they betrayed the trust of God, the Holy and Supreme. Someone who is related to us, even if in a menial position, if he errs, we become embarrassed. You are related to the Apostle of Allah, may the peace and blessings of Allah be with him and his progeny; by entering the seminary, you have related yourself to the Law of Islam, the most Noble Apostle and the Noble Qur'an. If you perform ugly deeds, it upsets the Prophet and he cannot bear it, and God forbid, you may be damned. Do not let the Apostle of Allah, peace be upon him and his progeny, and the pure Imams become upset and saddened.
The heart of man is like a mirror, clear and bright, and because of too much attention of this world and too many sins, it becomes dark. However, if a person at least performs the fast for God, the Almighty, sincerely and without duplicity (I am not saying that other acts of worship are not to be pure; it is necessary for all of the acts of worship to be performed sincerely and without duplicity), then this worship which is a turning away from lust, putting aside pleasure, and cutting oneself off from all but God, if it is performed well in this single month, perhaps the grace of God will be extended to him and the mirror of his heart will be cleaned of its blackness and tarnish; and there is hope that he will change his ways and become dissuaded from this wilderness and worldly pleasures. When the Night of Power [Laylat al-Qadr] ° arrives, one will gain the illumination which is obtained on that night by the riends of God and the believers.
Source:” The Greatest Jihad” by imam khomeini