Zaini Dihlan Sheikh al-Islam, the Mufti of Masjid al-Haram (the greatest mosque in the world), about Muhammad ibn Abdul Wahhab, in the book of Alderar Al Sunniah Fi Alrad ala Al Wahhabiah says that he considered the Muslims before his age as "infidels" and made Muslims confess their infidelity before converting to Wahhabism.He explains about it:
إذا أراد أحد أن يتبعهم على دينهم طوعا أو كرها، يأمرونه بالإتيان بالشهادتين أولا ثم يقولون له إشهد على نفسك إنك كنت كافرا و إشهد على والديك إنهما ماتا كافرين و إشهد على فلان و فلان إنه كان كافرا و يسمون له جماعة من أكابر العلماء الماضين، فإن شهدوا بذلك قبلوهم و إلا أمروا بقتلهم و كانوا يصرحون بتكفير الأمة من منذ ستمائة سنة.و اول من صرح بذلک محمد بن عبدالوهاب، فتبعوه في ذلک. و اذا دخل انسان في دينه و کان قد حجّ حجة الاسلام قبل ذلک يقولون له: حجّ ثانياً؛ فانّ حجتک الأولي فعلتها و انت مشرک فلاتسقط عنک الحجّ. ويسمون من اتبعهم من الخارج المهاجرين و من کان من اهل بلدهم يسمونهم الانصار
Anyone who wanted to convert to Muhammad ibn Abdul Wahhab's religion, was forced to confess that they have been infidels before, also confess that their parents have left the world being infidels and confess that such scholar and that scholar has died infidels. And he named many other great scholars who lived before, if the person confessed that they all were infidels he would then accept his confession otherwise he would kill them. They announced the entire Umma who lived 600 years before, "infidels". The first person introduced such innovation was Muhammad ibn Abdul Wahhab. The others, followed him and if anybody who accepted his religion had already done Haaj, they were ordered to redo their Haaj, as the previous one was done in the time of their infidelity (paganism) and so was not accepted! He called his followers Ansaar (supporters) if they were from his region, and if they were from other regions, called them Muhajirin (immigrants).
Then, the book reports about ignoring religious books by Muhammad ibn Abdul Wahhab and killing his criticizers:
