Scholars over time unanimously agree that:
a. Where the Qur’an and Hadith Mutawatir (which are qati’ al-thubut) are explicitly clear and unambiguous in their meaning and implications (qat’i al-dilalah), there is no debate or difference of opinions among scholars.
b. Those teachings that are based on these (clearly understood and indisputably authentic sources) form the core of what it is to be a Muslim. Qat’i texts are the bases for fundamental creed (aqidah), ritual worship (ibadat) and the most essential social transactions (mu’amalat), and therefore are bases for establishing whether a person is a Muslim or not.