As Salaam Alaykum,
I've read many Islamic books and I am not convinced that Islam as it is taught today is exactly what Prophet Muhammad and Companions actually practiced and believed. Like Ashari/Maturidi Aqidah, these schools really don't represent the Aqidah of Prophet Muhammad and His Companions but rather, the Aqidah of later scholars of Islam. The belief that the Quran is uncreated, is not the belief of Muhammad and His Companions, in fact we do not know what Prophet Muhammad and His Companions truly believed in this regard. So how can we say with certainty that the Ashari/Maturidi schools of Aqidah truly represent the Aqidah of Muhammad and His Companions, when the belief of that the Quran uncreated cannot be abolutely proven to be the belief of that early community.
If it is cannot proven with absolute certainty that it is belief of the Prophet Muhammad and Companions, why must those who choose not to believe in it are considered disbeliever (refer to Aqidah Tahawi), simply because the choose not to believe in it?
The same can be said in regards to issue related to fiqh and tasawwuf for that matter.