Question: It is stated in a hadith-i sharif that no sin causes kufr (disbelief) except shirk (polytheism). Apart from shirk, there are also sins that cause disbelief, as is known. Then what is the meaning of shirk that is mentioned in this hadith-i sharif?
Shirk means attributing partners to Allahu ta’ala. A person who does the attributing is called a mushrik (polytheist). There are kinds of disbelief. The worst, the gravest kind is shirk. It has been a generally accepted rule that when several subjects are to be referred to under one common nomenclature, the gravest one is mentioned. For this reason, the word shirk used in Qur’anic verses and hadith-i sharifs comprehends all sorts of disbelief.
The Qur’an al-karim says (what means):
(Allahu ta’ala never forgives shirk [all sorts of disbelief]. He forgives [all] sins [venial or grave] except shirk if He wills.) [An-Nisa’ 48]
As a disbeliever becomes a Believer by saying Kalima at-Tawhid once, so a Believer becomes a disbeliever by saying one word. He who says something that causes disbelief will lose his faith without even noticing it. A hadith-i sharif says:
(A time will come that a person will lose his faith without even noticing it. Faith will go out of him as a shirt is taken off.) [Daylami]
Whoever falls into disbelief, rewards (thawab) of all of his acts of worship will become null and void. If he repents, they will not be returned. He must renew his nikah, too. It is not enough only to say the Kalima ash-Shahadah for repentance. Repentance for the thing that caused one’s apostasy is required, too. If he does not know the things that caused him to fall into disbelief, it is enough to say, “I repent of all my statements and actions that caused disbelief.”
It is written in the books Bariqa, Hadiqa, and Majma’ul-anhur:
“If a Muslim, male and female alike, makes a statement or commits an act [consciously and without being subjected to duress] that he or she knows Islamic scholars unanimously define as one of the statements or acts that will cause one to become a disbeliever, he or she will lose his or her faith (iman) and become a murtad (apostate), even if the statement has been made or the act has been committed for a jocular purpose or without really thinking of its meaning. This sort of disbelief is termed kufr-i-inadi [disbelief out of obstinacy]. It causes one to become an apostate, to do so purposely, even if one does not know that the statement or the act concerned causes a state of disbelief. In this case the state of disbelief lapsed into is called kufr-i-jahli [disbelief out of ignorance] because it is fard for every individual Muslim to learn those Islamic facts that they have been enjoined to know. Not to know them, therefore, is a grave sin, instead of an excuse. People who have lost their faith by way of kufr-i-inadi or kufr-i-jahli will also lose their nikah (state of being married according to Islam’s canonical code). What a male Muslim, who has in this way lost his nikah, has to do is, getting a verbal proxy from his wife first, renew his nikah through a process termed tajdid-i-nikah, which is performed in the presence of two (male Muslim) witnesses or among the congregation in the mosque. Hulla is not necessary for tajdid (renewal of nikah) that a Muslim has had to perform more than twice. If a Muslim makes a statement causing a state of disbelief by mistake or in an interpretable way or under duress, he will neither become an apostate nor lose his nikah. If a person consciously makes a statement that is a matter of disagreement among the Islamic scholars as to whether it should be listed with acts causing a state of apostasy, he will not become an apostate, but he should make repentance, seek forgiveness, and renew his nikah for a margin of safety.”
(When a person falls into disbelief in either of the two ways [kufr-i inadi or kufr-i jahli], his previous acts of worship will become null and void. They are not returned even if he makes repentance. If he is rich, he has to perform the hajj again. It is not necessary for him to reperform his previous salats, to fast again, or to pay again the zakat he gave. It is not enough only to say the Kalima ash-Shahadah for repentance. Repentance for the thing that caused one’s apostasy is required, too. If a person makes a statement causing a state of disbelief by mistake or in an interpretable way or if he consciously makes a statement which is a matter of disagreement among the Islamic scholars as to whether it should be listed with acts causing a state of apostasy, he will not become an apostate. But he had better renew his faith.)