What is major Shirk?

Polytheism (Shirk) is divided into major (Akbar) and minor (Asghar). Major polytheism is divided into three categories:

The first category: Polytheism in Lordship (Rububiyyah), which has two types: Shirk of تعطيل (nullification), like the polytheism of Pharaoh and those who nullify the names and attributes of the Lord; and the polytheism of those who ascribe another lord alongside Allah, such as the Christians, the Magians, and those who believe in celestial bodies.

The second category: Polytheism in the Oneness of Names and Attributes (Tawhid al-Asma' wa al-Sifat), which has two types: likening the Creator to the created, such as the polytheism of the Mushabbihah (anthropomorphists); and deriving names for false deities from the names of the True God.

The third category: Polytheism in the Oneness of Divinity and Worship (Tawhid al-Ilahiyyah wal-Ibadah), which has three types: Polytheism in rituals and rites by offering supplication, vows, slaughter, and seeking aid to other than Allah; polytheism in obedience by permitting and forbidding what Allah has not authorized; and polytheism in love by loving other than Allah as one should love Allah.

As for minor polytheism, it is everything forbidden by the Law (Shari'ah) that serves as a means to major polytheism and a way of falling into it, such as ostentation (riya') and swearing by other than Allah. It does not expel its perpetrator from the faith, but its sin is greater than that of adultery and drinking alcohol.