- Polytheism is the gravest of all major sins. The Prophet ﷺ said, “Shall I not inform you of the gravest of the major sins?” We replied, “Yes, O Messenger of Allah.” He said, “Associating partners with Allah and disrespecting one’s parents.” (1)
The eminent scholar Ibn al-Qayyim (2) explained: Allah, exalted be He, has declared that the very purpose of creation and command is that He be known through His names and attributes, worshipped alone without partner, and that people uphold equity (qisṭ)—the justice upon which the heavens and the earth stand firm, as He says: “Indeed, We sent Our messengers with clear proofs, and We sent down with them the Book and the Balance so that mankind may uphold justice.” ⦗al-Hadid: 25⦘
Thus Allah has informed us that He sent His messengers and revealed His scriptures so that people may establish justice; the greatest form of justice is monotheism, the head and foundation of all justice. Conversely, polytheism is injustice, as He says: “Indeed, associating partners with Allah is a great injustice.” ⦗Luqman: 13⦘
Therefore, shirk is the darkest of all injustice, and tawḥīd is the most perfect form of justice. Whatever most directly contradicts this purpose is, therefore, the gravest of the major sins—until [the remainder of his words].