Will Allah forgive a Muslim. If he/she committed major/minor shirk unknowingly and dies without repentance of that shirk?
Abu Dharr reported: The Messenger of Allah, peace and blessings be upon him, said, “Verily, Allah has pardoned my nation for their mistakes, their forgetfulness, and what they are coerced into doing.”
Source: Sunan Ibn Mājah 2043
Grade: Sahih (authentic) according to Al-Albani
عَنْ أَبِي ذَرٍّ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِنَّ اللَّهَ تَجَاوَزَ عَنْ أُمَّتِي الْخَطَأَ وَالنِّسْيَانَ وَمَا اسْتُكْرِهُوا عَلَيْهِ
2043 سنن ابن ماجه كتاب الطلاق باب طلاق المكره والناسي
1675 المحدث الألباني خلاصة حكم المحدث صحيح في صحيح ابن ماجه
I opined that if a person committed shirk in error or forgetfulness, Allah will forgive him provided he believes that there is no God but Allah.
A Muslims is expected to study and learn more about his religion.
In Sunan Abu Dawud 3636, Abu Hurairah reported the Prophet (ﷺ) as saying:
If anyone pursues a path in search of knowledge, Allah will thereby make easy for him a path to paradise; and he who is made slow by his actions will not be speeded by his genealogy.
Shirk is a major sin in Islam and an affront to Allah's mercy (swt). You would expect a Muslim to know what is and what isn't shirk before he reaches an age or condition near the hour of death. Whenever we commit sins, big or small, intentional or unintentional, we should ask Allah (swt) for His forgiveness.
As for Muslims who have died without repenting unintentional shirk, let us simply pray for them that Allah (swt) pardons them because of their ignorance. I am under the opinion that Allah (swt) would forgive Muslims who are sincerely repentant on their deathbeds regardless if they have committed sins intentionally or otherwise.
In Surah Az-Zumar 39:53, it was revealed:
۞ قُلْ يَا عِبَادِيَ الَّذِينَ أَسْرَفُوا عَلَىٰ أَنْفُسِهِمْ لَا تَقْنَطُوا مِنْ رَحْمَةِ اللَّهِ ۚ إِنَّ اللَّهَ يَغْفِرُ الذُّنُوبَ جَمِيعًا ۚ إِنَّهُ هُوَ الْغَفُورُ الرَّحِيمُ
Say, "O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful."
Allah knows best.
بسم الله الرحمان الرحيم
Shirk is the biggest sin committable. From what I understand, as long as the shirk was committed unknowingly, then understood and repented for, Allah will graciously forgive [the doer].
وَإِذَا جَاءَكَ الَّذِينَ يُؤْمِنُونَ بِآيَاتِنَا فَقُلْ سَلامٌ عَلَيْكُمْ كَتَبَ رَبُّكُمْ عَلَى نَفْسِهِ الرَّحْمَةَ أَنَّهُ مَن عَمِلَ مِنكُمْ سُوءًا بِجَهَالَةٍ ثُمَّ تَابَ مِن بَعْدِهِ وَأَصْلَحَ فَأَنَّهُ غَفُورٌ رَّحِيمٌ When those come to you who believe in Our Signs, say: "Peace be on you! Your Lord had inscribed for Himself (the rule of) Mercy. Verily if any of you did evil in ignorance, and thereafter repented and amended (his conduct), Lo! He is Oft-Forgiving, Most Merciful. Surat Al-Anaam, Verse 54
However, I do not know of the situation that the Mushrik does not realize his doing of Shirk. In this Aya, Allah says that those who realize their doing of Shirk after doing it unkowingly and repent for it, are forgiven.
It is always best to learn as much as possible about Shirk to avoid accidentally committing it
And Allah knows best.
Islam is quite clear about what constitutes shirk in its most basic aspects. It's unlikely then for a Muslim not to know what shirk is and how it is to be avoided.
According to one Islamic Scholar, a Muslim may neglect one or more of the pillars of the faith, and still be counted alongside with the ummah, so long as they still believe in the necessity of the five pillars and so long as they do not repudiate th Shahadah.