Muhammad b. 'Abd al-Wahhab in Context
Groups that want to strictly implement Islamic law are, however, a dime a dozen throughout history, as the records of many Anatolian preachers during Ottoman times will attest. What most distinguishes the message of Muhammad b. 'Abd al-Wahhab in its 18th-century context is found in the fouth chapter of his Kitab at-Tawhid, which, commenting on various Qur'an verses, says:
"That it proves that the meaning of Tawheed and the testimony Laa ilaaha illallah is the abandonment of the deeds of the polytheists such as calling upon the Prophets and the Righteous and requesting their intercession with Allah ; and the verbal recitation of the testimony is not sufficient if the worship of all deities besides Allah is not rejected...
"Allah , informs us in this verse that some of mankind set up for themselves deities which they love more than they love Allah , then He, Most Glorified explains that the Believers are stronger in their love for Allah than the polytheists because the Believers are pure and sincere in their love of Allah , Alone, while the polytheists divide their love between Allah and their false gods; and whoever was sincere in loving Allah , Alone, his love would be stronger than that of the polytheist who divides his love. Then Allah , Most Glorified promises those who associate partners with Him that when they see the punishment which He has prepared especially for them on the Day of Resurrection, they will wish that they had not associated others with Allah , either in love, or in anything else. Then they shall know, with certain knowledge that all power belongs to Allah , and that Allah is Stern in enforcing His punishment...
"That it proves that the meaning of Tawheed and the explanation of the shahaadah: Laa ilaaha illallaah are not complete without a categorical rejection of all that is worshipped besides Allah."
As explained clearly by David Commins in his The Wahhabi Mission and Saudi Arabia, this sets up the Wahhabi argument, made in specific detail later, the the shahada, or the profession of faith that "There is no God but God and Muhammad is the messenger of God," is incomplete unless one rejects the "worship," which non-Wahhabis would regard as a lesser veneration, of all beings besides God. An example that goes to the heart of traditional Islamic religious practice is found in the first excerpt, as Muslims routinely sought the intercession of Muhammad and various holy figures, and made pilgrimages to their tombs to seek blessings. The Wahhabi claim is, not only that such practices are wrong, but that they are sufficiently wrong that they render the shahada, the act by which one becomes a Muslim, invalid.
This denial of the genuine Islam-ness of those who claim to be Muslims, or takfir, represents a sharp break with the general inclusiveness displayed by mainstream Islam throughout history, and is probably one reason why primary sources from the 18th and early 19th century deride the Wahhabis as Kharijites, who in early Islam also practiced it. The takfiri trend, however, would unfortunately gain steam, and has become a significant marker for today's Salafi militants.