What are the controversial issues in which Sheikh Muhammad ibn Abd al-Wahhab was accused of extremism in accusing his opponents of polytheism (shirk) and innovation (bid‘ah), and is it permissible to accuse him of that without knowledge?

Shaykh Muhammad ibn Abd al-Wahhab is not proven to have declared any Muslim an infidel over a matter of scholarly disagreement. Rather, he declared someone an infidel based on matters upon which the people of knowledge have reached a consensus, such as one who directs any form of worship to other than Allah after the proof has been established. As he stated: "We only declare as an infidel one who associates partners with Allah in His divinity, after the proof for the nullity of polytheism has become clear to him." His sons and grandsons affirmed this position, indicating that he refrained from declaring even an ignorant person who invokes other than Allah an infidel if the proof had not reached him, and that he only declared as infidel those whom Allah and His Messenger declared infidel and upon whose infidelity the Ummah has reached a consensus, such as one who worships the righteous.