Accordingly, the disbeliever (kāfir) is, in the view of the scholars, of two kinds:

1. An original disbeliever: such as a Jew, a Christian, a Buddhist, or any of the other communities of unbelief.
2. The apostate (murtadd): one who embraced Islam and then fell into something that nullifies it and entails disbelief.

The Shaykh cites as proof for this category the words of Allah: “Indeed, Allah does not forgive associating partners with Him, but He forgives whatever is less than that for whomever He wills” (4:48); His words: “Whoever associates partners with Allah—Allah has forbidden Paradise to him, his refuge will be the Fire, and the wrongdoers shall have no helpers” (5:72); and His words: “It has been revealed to you and to those before you that if you should associate partners with Allah, your deeds would surely be rendered void and you would certainly be among the losers” (39:65).

This is major shirk (polytheism), and it has three characteristics:
First: it is not forgiven.
Second: it requires eternal residence in the Fire and makes Paradise forbidden to its perpetrator.
Third: it nullifies all deeds.

Whoever worships anything alongside Allah will find that every act with which he seeks to worship Allah is rendered void; indeed, his supposed worship of Allah is not even called worship, as the Shaykh remarks in certain chapters of Kitāb al-Tawḥīd: “Whoever fails to bring it has not worshipped Allah at all.” ⦗1⦘