By Mufti Muhammad Zubair Butt
The issue of takfir (declaring someone a kafir) is an extremely delicate issue and should be approached with extreme caution. It is a grave sin to declare a Muslim to be kafir or murtad (apostate). The Holy Qur’an states:
O you who believe! When you go in the cause of Allah, verify [the truth of all matters], and say not to anyone who greets you: “You are not a believer”; seeking the perishable goods of the worldly life for there are with Allah booties in abundance. Even as he is now, so were you yourselves before till Allah conferred on you His favours [i.e. guided you to Islam], therefore, be cautious. Indeed, Allah is Well-Aware of what you do. [4:94]
It is reported on the authority of Ibn ‘Umar (R) that the Messenger of Allah sallallahu `alayhi wa sallam said:
Any person who called his brother: Kafir, [has in fact done an act by which] one of them has returned with it. If it were so, as he asserted [then the unbelief was confirmed], but if it was not true, then it returned to him [who labelled his brother Muslim). [Sahih Muslim]
However, just as it is a grave sin to declare a Muslim to be a kafir or an apostate, it is equally incorrect to consider a kafir to be a Muslim without due consideration to the erroneous beliefs he may hold. In this regard the Holy Qur’an states:
Do you want to guide him whom Allah has made go astray? And he whom Allah has made to go astray, you will never find for him any way [of guidance]. [4:88]
Therefore, before submitting a direct answer to your question, it is important to first discuss the basic principles according to which one who was previously a Muslim may be considered to be an apostate. There are two fundamental ways in which one who was previously a Muslim may be considered to be an apostate:
One who was previously Muslim totally renounces Islam [ والعياذ بالله ] and adopts another religion such as Christianity, Judaism, Buddhism, etc. or denies the existence of Allah (SWT) entirely, or the concept of tawhid or denies the prophethood of Rasulullaah sallallahu `alayhi wa sallam. Such a person is undoubtedly an apostate.
Although one who was previously Muslim does not renounce Islam and adopt another religion, nor deny the existence of Allah (SWT) or the concept of tawhid or the prophethood of Rasulullaah sallallahu `alayhi wa sallam, but adopts beliefs that amount to the denial of the text of the Holy Qur’an or the prophethood of Rasulullaah sallallahu `alayhi wa sallam. For example, such person denies an injunction established through a text of the Holy Qur’an that is definitive in its meaning or through a definitive mutawaatir hadith of Rasulullaah sallallahu `alayhi wa sallam. Such a person is also considered to be an apostate by the consensus of Muslims.
To elucidate further, in the latter case, apostasy will only apply if one denies an absolute injunction ( الحكم القطعى ) that has been established from evidence that is unquestionably established قطعى الثبوت (qat‘i al-thubut) and unquestionable in its purport قطعى الدلالة (qat‘i aldilalah), i.e. it does not admit more than its one apparent meaning. This can be either through a text of the Holy Qur’an that is definitive in its purport or through a mutawaatir hadith (prophetic tradition that has been transmitted to us via indisputably authentic chains of authority) that is definitive in its purport.
Then, if the knowledge of such absolute injunctions is widespread amongst the Muslim masses to the extent that one does not have to venture to any great length to acquire knowledge of them, such as the injunctions of Salaah, Zakaah, Hajj, and fasting, the prohibition of theft and the consumption of wine, such injunctions are referred to as ‘dharooriyyaat al-deen’ (essentials of deen). If the knowledge of such injunctions is not so wide spread, then although they are absolute injunctions there are not referred to as ‘dharooriyyaat al-deen’ (essentials of deen). The difference in the ruling between the two is that the denial of those absolute injunctions that are also from the ‘dharooriyyaat al-deen’ (essentials of deen) immediately renders one apostate according to the consensus of the Muslims. Ignorance is not considered to be an excuse, and any other divergent interpretation is unacceptable. With regards to those absolute injunctions whose knowledge is not widespread amongst the Muslim masses to the extent mentioned above, denial of such injunctions will not immediately render one an apostate. Instead, one will be made aware that the injunction in question is an absolute injunction that has been established from evidence that is unquestionably established قطعى الثبوت (qat‘i al-thubut) and unquestionable in its purport قطعى الدلالة (qat‘i aldilalah). If one still continues in one’s denial, one will be considered an apostate.
However, if one does not deny such injunctions, even if one’s practice is to the contrary, although one will be considered a transgressor, one will not be declared an apostate.
In short, just as renouncing Islam and adopting another religion is apostasy, in the very same manner, to deny an absolute injunction, or offer an interpretation that is contrary to the established interpretation is also apostasy. The latter form of apostasy is referred to in the Qur’an as Ilhaad:
Indeed, those who deviate in Our verses [by attributing self assumed meanings to them that are contrary to the clear and explicit meanings recognised by the ummah and that change the intention of the Holy Qur’an in it’s entirety] are not hidden from Us. [41:40]
The scholars of scholastic theology and jurisprudence refer to such apostasy as baatiniyyah and also zandaqah as ‘Allaamah Sa‘d al-Din al-Taftaazaani has done in Sharh al-Maqaasid.
From: https://www.ilmgate.org/what-is-the-status-of-one-who-considers-homosexuality-to-be-permissible/