Throughout the age of Islam and up to the present time a persistent issue and subject that was often discussed and written about was that on takfir, which is basically the act of pronouncing a Muslim to be a non-Muslim. The reason this subject has been thoroughly discussed and dealt with time and time again is because throughout the age of Islam up to our present day, we have had several heretics and ignorant Muslims who have been making wide takfir on the general masses, or making takfir on specific Muslims due to their ignorance and lack of understanding on this matter.
This is still an issue in our present day, where we have several Muslims labelling other Muslims as being non-Muslims, and therefore to assist my fellow brothers and sisters I have decided to write this article which establishes the main conditions on takfir, conditions which have been laid down in the Quran, the sunnah, and which have been unanimously agreed upon the scholars (ulamah).
So therefore with all of this said, let us now proceed to the conditions of takfir, and what actually draws a Muslim outside the fold of Islam, and that which doesn't not throw the Muslim outside the fold of Islam.
As we all know the Quran and the sunnah have given us several rules and laws to live by, the Quran and sunnah have made it clear upon us on that which is haram (forbidden) and that which is halal (accepted/okay/no sin). Here is an example taken from the noble Quran:
YUSUFALI: Satan's plan is (but) to excite enmity and hatred between you, with intoxicants and gambling, and hinder you from the remembrance of Allah, and from prayer: will ye not then abstain?
So as you can see alcohol and gambling is prohibited in Islam, it is a major sin (haram). However so not only is it forbidden to drink alcohol or take part in gambling, it is forbidden to have anything to do with these 2 things, including selling alcohol, transporting it, and the same for gambling, it is forbidden to own a casino or have anything to do with the gambling industry.
Now let us say a Muslim openly drinks alcohol and gambles, this is indeed a major sin, and he will have to repent from these major sins as soon as possible or he will have to face the consequences in the hereafter when he is brought to be judged by his Lord and Master.
Now what we do not say is that this Muslim is an apostate and has become a disbeliever because of this major sin, no, this is what the heretics do such as the takfiris and muatazila, who make open takfir on Muslims based on their major sins. Rather the correct method is that we say this Muslim has committed a major wrong, and must repent to his Lord. We do not call him an apostate, nor do we claim that he is a disbeliever and no longer a Muslim.
The same goes for any other major sin, whether it be gambling, adultery, fornication, murder, theft, and whatever major sin that we have been warned off. (On a side note the only major sin that automatically makes one a disbeliever and an apostate is shirk, this is the only major sin that throws one outside the religion of Islam.
Now if this Muslim commits major sins, such as drinking alcohol, and gambling, and then he says it is not haram (forbidden) and that it is halal (acceptable/okay/no sin) and that what he is doing is perfectly okay and that he has no need to repent or fear then it is for this person whom takfir can be pronounced upon as he has met the condition for it. This Muslim BELIEVES what he is doing is essentially okay, and Muslims always judge a person firstly based on his intention before the action, it is what is in the heart that really matters, so if a Muslim believes that these major sins are permissible and are not haram then we say he has disbelieved and has become an apostate and must repent back to the straight path.
So do you see the difference in the two? A Muslim who commits a major sin does not become an apostate based on the sin, unless it happens to be shirk, the Muslim becomes an apostate based on his belief concerning the sin he has committed, if he commits the major sin and believes that what he is doing is wrong, and that he must repent later, and that he may be punished if he does not then we say he is not an apostate but a misguided Muslim who is in need of help. However so if the Muslim commits the sin and believes it is not haram, and that it is halal then we say he has disbelieved and is an apostate.
Most of the time the issue of takfir is based on the belief more than the action, but this is not always the case, a Muslim may become an apostate and a disbeliever for an action as well, and this action is that of mocking the religion and the prophet. It does not matter at all that if he believes that Islam is the truth, if he makes fun of it or jokes about it even with the belief that Islam is true he is still an apostate and must repent from this evil deed. As Imam an-Nawawi wrote in "Kitaab ur-Riddah" (The Book of Apostasy):
"It is the cutting off of Islaam. This occurs sometimes by a statement which constitutes kufr, and sometimes by an act. And the actions which necessitate kufr (that expel from the religion) are those which are performed deliberately, and mocking the religion is clear [in this regard], such as prostrating to an idol or to the sun, or throwing the Qur-an into filth, and the magic which involves worshipping the sun and other such acts."
So takfir is not limited to beliefs alone as some heretics claim, they are known as the murjiah, they basically say someone is saved on faith alone, and if he has faith and belief then it doesn't matter what sinful action he does, he is still a Muslim, even if he bows to an Idol, sacrifices to an Idol, and insults the religion!
So let us summarize what we have so far:
1-A Muslim does not become an apostate based on a major sin he has commited
2-A Muslim becomes an apostate if he claims that his major sin is not haram but halal
3-A Muslim may become an apostate by belief AND actions, it is not based on belief alone.
With that said we now move upon the ignorant Muslim, the Muslim who does not know his religion and the shariah. For this Muslim we say he can be excused, for instance if he commits a sin and doesn't think its haram because he is ignorant and does not know, we say he is not an apostate. However so what we do is we educate this Muslim on his religion, and the shariah, and when we make it clear to him what is haram and what is halal yet he still persists in his misguided wrong beliefs even after the evidence and proof has been given to him then we say he is an apostate. Now having said that a Muslim who worship's idols and so on we say he is not even a Muslim, even if he thinks he is a Muslim and is ignorant, we still say he is not even a Muslim, what we do is we teach him the religion as it seems he does not even know what Islam is!
Every Muslim at least knows and believes the basics of Islam, which is that there is only one God, and that this God is the only one whom we should worship, and that Muhammad is his prophet, this is the very least basics any Muslim should know, ignorant or knowledgeable, a Muslim who does not even know these basic principles is not even a Muslim! He is a Muslim by name only, not in belief and action, so therefore whatever he does does not matter as he never was a Muslim to start with.
So hopefully all of this shall help you understand the proper conditions of takfir, and who becomes a non-Muslim.
Last but not least it must be said that takfir should be reserved with those who know and have studied their faith, and are good enough to defend it and preach it, basically the scholars and teachers, takfir is not to be done or pronounced by your average knowledge Muslim. The issue of takfir is not something that must be played with as a consequence of making wrong takfir is very dangerous and in fact makes a Muslim an apostate! As the Islamic sources teach us:
Volume 8, Book 73, Number 71:
Narrated Abu Dhar:
That he heard the Prophet saying, "If somebody accuses another of Fusuq (by calling him 'Fasiq' i.e. a wicked person) or accuses him of Kufr, such an accusation will revert to him (i.e. the accuser) if his companion (the accused) is innocent." ( Sahih Bukhari)
Sahih Muslim Book 001, Number 0116:
It is reported on the authority of Ibn 'Umar that the Apostle (may peace and blessings be upon him) observed: When a man calls his brother an unbeliever, it returns (at least) to one of them.
And indeed Allah knows Best!