Can someone repent for shirk? Like repent in this life, and could be forgiven? Or you can't repent for shirk at all, and you are doomed, maybe? Can someone tell me, are you able to repent for shirk or will you be doomed, if you did shirk, maybe?
Of course you can. Doesn't matter if you were a Muslim or non-Muslim, you can always repent.
What is to become a Muslim? It is accepting the existence and oneness of God and Mohammad(puh) as Allah's messenger to teach us about Allah and his orders. If you truely believe as this, and if you say it loudly (at least to yourself), you will become a Muslim.
What is shirk then? Shirk is putting something else in the place of God. This may be another god, may be a half-god, fire, nature, your mind, a woman, money etc. It doesn't matter if you are a polytheist, an atheist or a monotheist with a god other than Allah (sun for example, there were people who worship sun). How can someone do this? Either by ignorance or by arrogance.
If you are trying to repent, this means you either gain some knowledge to accept Allah as one true god, or you defeated your arrogance. In either case, if you are sincere, why doesn't Allah forgive you? Is there a just one minor reason?
Why Allah created us? To know him, to admire him, to worship him. Now, you want to do that, but he says no. Why? Isn't it what he wants?
Furthermore, if Allah doesn't forgive who repent, then there won't be any Muslim but prophets.
Lets take a look at some verses. These are for non-Muslims:
And if any one of the polytheists seeks your protection, then grant him protection so that he may hear the words of Allah . Then deliver him to his place of safety. That is because they are a people who do not know. (Surat At-Tawbah 9/6)
But if they repent, establish prayer, and give zakah, then they are your brothers in religion; and We detail the verses for a people who know. (Surat At-Tawbah 9/11)
These are clear and obvious. Even if you are in war, if they seek refuge from you, you have to take them away from battle so that maybe they will hear Allah's word and repent.
Now these verses are for non-Muslims who were once Muslims:
How shall Allah guide a people who disbelieved after their belief and had witnessed that the Messenger is true and clear signs had come to them? And Allah does not guide the wrongdoing people.
Those - their recompense will be that upon them is the curse of Allah and the angels and the people, all together,
Abiding eternally therein. The punishment will not be lightened for them, nor will they be reprieved.
Except for those who repent after that and correct themselves. For indeed, Allah is Forgiving and Merciful. (Surat 'Āli `Imrān 3/86-89)
How can a repentance won't be accepted? There are 2 verses about this issue:
Indeed, those who reject the message after their belief and then increase in disbelief - never will their [claimed] repentance be accepted, and they are the ones astray. (Surat 'Āli `Imrān 3/90)
But repentance is not [accepted] of those who [continue to] do evil deeds up until, when death comes to one of them, he says, "Indeed, I have repented now," or of those who die while they are disbelievers. For them We have prepared a painful punishment. (Surat An-Nisā' 4/18)
Here, the 2nd verse is very clear. If you repent while dying, it won't be accepted. What about the other one? There are different commentaries about who are the ones that increase their disbelief:
- The People of Scripture. They didn't believe about Mohammad(puh)'s prophecy (kufr 1) and they acted the Prophet and Muslims with disrespect, denying miracles, breaking their oaths, ambushing them etc (kufr 2, 3, 4...)
- Jews. They first denied Jesus(puh) and Bible (kufr 1), then they denied Mohammad(puh) and Quran (kufr 2).
- Some people converted from Islam (kufr 1), then returned to Mecca and desired and said the failure of Mohammad(puh) (kufr 2).
- Some people converted from Islam (kufr 1), then they said they wanted to go back to Islam, but they were hypocrites (kufr 2).
- They may go ahead so much in kufr, their hearths will be locked by Allah and so the repentance won't be granted to them.
Allah has set a seal upon their hearts and upon their hearing, and over their vision is a veil. And for them is a great punishment. (Surat Al-Baqarah 2/7)
As you see, unless there is an extreme case (death, insistence with kufr etc), Allah accepts one's repentance if he is sincere about his repentance.
In the name of Allah , the Entirely Merciful, the Especially Merciful.
You definably have seen this everywhere because we always start with name of Allah. It says Allah is most merciful.
What is shirk?
If any person included something or somebody with Allah and say "they are same". Like other religious man says "your God and our God", this is shirk and this is the sin which Allah doesn't like.
Some ayah related to Shirk.
But only one who comes to Allah with a sound heart. Surat Ash-Shu`arā - 89
and another ayah which says how bid sin this is.
And [mention, O Muhammad], when Luqman said to his son while he was instructing him, "O my son, do not associate [anything] with Allah . Indeed, association [with him] is great injustice. Surat Luqmān - 13
And a hadith related to Shirk
I heard Anas say: 'The Messenger of Allah [SAW] said: The major sins are: Associating others with Allah (Shirk), disobeying one's parents, killing a soul (murder) and speaking falsely. Sunan an-Nasa'i 4010 - Book 37, Hadith 45
Would Allah forgive a person who commit this sin?
If somebody accepts Islam, he would be like new baby who is completely sinless.
Those people who are in other religion are doing shirk. They are worshiping other than Allah so when they would accept Islam, they would be like new baby.
Note : It is most important a person repent in his life.
Allah swt says in many iyat that he forgives the one who repents. A person can repent from any sin be it shirk, munafiq, kufr, etc.
Allah swt says,
"۞ قُلۡ يَـٰعِبَادِىَ ٱلَّذِينَ أَسۡرَفُواْ عَلَىٰٓ أَنفُسِهِمۡ لَا تَقۡنَطُواْ مِن رَّحۡمَةِ ٱللَّهِۚ إِنَّ ٱللَّهَ يَغۡفِرُ ٱلذُّنُوبَ جَمِيعًاۚ إِنَّهُ ۥ هُوَ ٱلۡغَفُورُ ٱلرَّحِيمُ ۞"
And the interpretation of the meaning, by Yusef Ali:
"Say, O my Servants who have transgressed against their souls! Despair not of the Mercy of Allah, for Allah forgives all sins: for He is Oft-Forgiving, Most Merciful."
Say to those who have disbelieved [that] if they cease, what has previously occurred will be forgiven for them. But if they return [to hostility] - then the precedent of the former [rebellious] peoples has already taken place. Al'Anfal 38 (8:38)
قال ابن كثير في تفسيرها: قل للذين كفروا إن ينتهوا عما هم فيه من الكفر والمشاقة والعناد، ويدخلوا في الإسلام والطاعة والإنابة، يغفر لهم ما قد سلف، أي من كفرهم وذنوبهم وخطاياهم.. (2407).
Ibn kathir sad in the tafsir : Say to those who disbelieve (make shirk act ), if they finish what they are doing of disbelief and stubbornness (the shirk) , and enter into Islam and obedience,them ancestor will be forgiven ( forgiven any of their disbelief and sins)
So yes my friend if you repent and you announce Shahada again god will forgive you.