On the issue of whether ignorance is a valid excuse
Question

I have some relatives who are Sufis, and they follow whatever their shaykh tells them, because they believe he is a man of knowledge. They have practices that come under the heading of major shirk, but they do that on the basis of their own interpretations. They do not know the Arabic language, but they have a translation of the meanings of the Qur’an in their mother tongue, although they do not read it. I have read that there is no valid excuse for a Muslim to commit major shirk; that is, if he is able to read the Qur’an and is able to find a copy of the Qur’an in the land where he is living, or if he is able to make contact with the scholars and ask them, and refer issues to them.
Is it obligatory for me to regard them (my relatives) as disbelievers? Or do I have to warn against regarding them as disbelievers?
Praise be to Allah.Firstly:
What is required of the Muslim is to understand and believe in Tawheed (the Oneness of Allah) and to follow the Qur’an and Sunnah according to the understanding of the righteous early generations (salaf), and to avoid innovation (bid‘ah) and its people. The Sufi tariqahs (paths) come under the heading of people of innovation, so the Muslim should keep away from their path and not follow in their footsteps.
Secondly:
It is not permissible to take the issue of calling a Muslim a disbeliever (kaafir) or an evildoer (faasiq) lightly, because that comes under the heading of fabricating lies against Allah and fabricating lies against His Muslim slaves. It is not permissible to call a Muslim a disbeliever or an evildoer unless he commits that which would support that appellation in word or deed, based on clear evidence from the Qur’an and Sunnah.
Moreover, it is not permissible to call him a disbeliever or evildoer until all conditions required for calling him such are met, and all impediments to that are absent.
One of those conditions is that he should be aware that his words and practice contradict the teachings of Islam, which led to him becoming a disbeliever or evildoer.
One of the impediments to that is if he bases his action on a misinterpretation, or he may have some specious argument that he thinks provides evidence for his practice, or he is in such a situation that he cannot understand the shar‘i evidence in a proper manner. A person can only be deemed a disbeliever after there is certainty that he is deliberately going against the teachings of Islam and he is not ignorant of the issue.
For more information on the guidelines on whether or not a person may be deemed a disbeliever, please see the answer to question no. 85102.
Thirdly:
The correct view with regard to the issue of ignorance and whether ignorance is a valid excuse is that if a Muslim is proven to be a Muslim, he cannot be stripped of this description on the basis of mere doubt; rather he cannot be stripped of this description except on the basis of certainty and after establishing proof against him in such a way that leaves him with no excuse.
Shaykh Muhammad ibn ‘Abd al-Wahhaab (may Allah have mercy on him) said:
If we do not describe as a disbeliever one who worships the idol  on the grave of ‘Abd al-Qaadir or worships the idol on the grave of Ahmad al-Badawi [the “idols” in question are structures over the graves, to which some people devote practices that constitute worship], and the like, because of their ignorance and because there is no one who ever alerted them to their mistake, then how could we regard as a disbeliever one who never associated anything with Allah if he does not migrate to us, or if he does not regard others as disbelievers and fight them? “Exalted are You, [O Allah]; this is a great slander” [an-Noor 24:16].
End quote from ad-Durar as-Saniyyah (1/104)
it is well-established that basically these non-Arabs have grown up in countries and societies where ignorance of many of the rulings and teachings of Islam is the norm, especially with regard to issues having to do with the Sunnahs and also the foundations of Tawheed. Rather they believe in general terms, but are ignorant of many of the details.
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said:
Regarding someone as a disbeliever is like a warning of hellfire, even if it is because the one who is so described is saying something that implies rejection of what the Messenger taught; that man may be new in Islam, or may be living in the wilderness, far from centres of teaching.
Such a person should not be deemed a disbeliever for something he rejected of the teachings of Islam until proof has been established in his case. A man may not have heard of some particular text, or he may have heard of it but it was not proven to him to be sound and correct, or he may have already some idea established in his mind that contradicts the text and so he misinterpreted the text.
I always remember the hadith in as-Saheehayn about the man who said: “…When I die, burn me then crush (my bones), then scatter me in the wind and in the sea, for by Allah, if Allah grasps hold of me, He will punish me as He has never punished anyone. They did that to him, then He said to the land: Return what you have taken, and he was standing there. Then He said to him: What made you do what you did? He said: Fear of You, O Lord. And Allah forgave him because of that.”
This was a man who doubted the might of Allah, and doubted that He would be able to bring him back to life after his ashes were scattered; in fact he believed that he would not be resurrected, which constitutes disbelief according to the consensus of the Muslims. But he was ignorant and did not know that, yet he was a believer who feared that Allah would punish him, so Allah forgave him because of that.
If a person misinterprets a religious text when he is qualified to engage in ijtihad and is keen to follow the Messenger, it is more appropriate that he should be forgiven than someone like the person who is mentioned in the hadith.
End quote from Majmoo‘ al-Fataawa (3/231).
He also said:
Many people may grow up in places and times where there is not much left of knowledge of the revelations of Allah, to the extent that there is no one left who can teach others that with which Allah sent His Messenger of the Book and wisdom, so they do not know much of that with which Allah sent His Messenger, and there is no one there to teach them that. Such people cannot be deemed disbelievers. Therefore the leading scholars were unanimously agreed that whoever grew up in the wilderness, far away from people of knowledge and faith, and is new in Islam, if he rejects some of these well-known, mutawaatir rulings of Islam, he is not to be deemed a disbeliever until he learns the message with which the Messenger was sent.
End quote from Majmoo‘ al-Fataawa (11/407).
Their merely knowing a translation of the meanings of the Qur’an is not enough; rather even if they are able to read it in Arabic, that is not enough. How many of those who speak Arabic and have some knowledge of the language still cannot understand from reading the texts of the Qur’an and Sunnah that what they are doing is wrong or invalid, or whether it is shirk or not.
Al-Haafiz Ibn Hajar (may Allah have mercy on him) said:
Al-Ghazaali said in his book at-Tafriqah bayna al-Eemaan wa’z-Zandaqah: What we must be very careful not to do is to call people disbelievers, and we should avoid that as much as possible, for the error in not labelling one thousand disbelievers as a disbelievers is less grave than the error of shedding the blood of one Muslim.
End quote from Fat-h al-Baari (12/300).
What the questioner in this case should do is strive to call his relatives and acquaintances by teaching them true Tawheed and Sunnah, and bearing with patience their offence, rejection and harshness. The greatest attitude that he can have towards people is as Allah, may He be exalted, says (interpretation of the meaning):
“And who is better in speech than one who invites to Allah and does righteousness and says, "Indeed, I am of the Muslims’?
And not equal are the good deed and the bad. Repel [evil] by that [deed] which is better; and thereupon the one whom between you and him is enmity [will become] as though he was a devoted friend.
But none is granted it except those who are patient, and none is granted it except one having a great portion [of good].
And if there comes to you from Satan an evil suggestion, then seek refuge in Allah . Indeed, He is the Hearing, the Knowing”
[Fussilat 41:33-36].
See also the answer to question no. 111362
And Allah knows best.