Polytheism is the greatest of sins. In the Arabic language, it is called shirk. It means ascribing partners with God in His Divinity or any of His Attributes. The Prophet Muhammad ﷺ was asked, “Which is the greatest sin?” He replied, “That you set up with Allah a rival and He is the One who created you.” (Bukhari and Muslim)
In the case of lesser sins, the matter is subject to Allah’s Will. If He wills, He will forgive the person who meets Him with that sin unrepented for, and if He wills, He will punish him. But in the case of shirk, God says that He will not forgive the person who does not repent to Him from it. So, in the case of commission of shirk, the matter is not that trivial.
The Qur’ān (4:48) says: “Surely Allah does not forgive that a partner be ascribed to Him, although He forgives any other sins for whomever He wills. He who associates anyone with Allah in His divinity has indeed forged a mighty lie and committed an awesome sin.”
Further, in the āyah 4:116 the Qur’ān says: “Truly it is only associating others with Allah in His divinity that Allah does not forgive, and forgives anything besides that to whomsoever He wills. Whoever associates others with Allah in His divinity has indeed strayed far away.”
Thus, these two ayaat show that the commission of shirk is forging ‘a mighty lie’ or committing ‘an awesome sin’, and a mushrik or polytheist ‘has indeed strayed far away’.
In the āyah4:117, the Qur’ān wonders at a person’s degrading himself from the high status of humanity by calling upon goddesses and even Satan: “Rather than call upon Him, they call upon goddesses, and call upon a rebellious Satan.” Maulana Maudoodi, while commenting on this āyahin his magnum opus Tafhīm al-Qur’ān, tells us how calling upon Satan is tantamount to worship him. He says: “No one sets up Satan as his ‘god’ in the sense that he makes him the object of his ritual worship and declares him to be God in so many words. The way to make Satan one’s god is to entrust one’s reins to him and let oneself be drawn helplessly in whichever direction he wants; the relationship between the two is, then, that of worshipper and worshipped. This shows that either absolute, unreserved obedience to or blind following of anybody is tantamount to ‘worshipping’ him, so that whoever indulges in this kind of absolute obedience is guilty of worshipping a ‘god’ other than the One True God.”
This brief discussion brings into light the futility of shirk because it endangers the end result of a person who commits it and destroys his prospect of winning the pleasure of God. Therefore, those who are in a state of unbelief and polytheism should reflect upon the universe around them and their own physical structure in right earnest so that they may see many signs indicating the existence of God and thereby realise the importance of Tawhīd or monotheism in human life.