The great Maaliki scholar, Imaam Shaatbi (rahimahullah) [d. 790 A.H.] writes:
The most effective and beneficial method of acquiring knowledge is to obtain it from its true bearers who possess it truly and completely.
People ask: “Is it possible to acquire knowledge without the medium of a teacher?”
While it is undoubtedly possible in the literal sense, the scholars are unanimous that by and large, learning under a teacher is necessary and self-study is practically impossible. They have also said: “Knowledge was in the hearts of men, then it moved to books; however its keys still lie in the hands of men (teachers).”
This statement advocates the necessity of acquiring knowledge from qualified teachers. The proof of this is an authentic hadeeth of Rasulullah (sallallahu ‘alaihi wasallam): “Indeed Allah Ta‘ala does not snatch away knowledge suddenly from the people. Instead, He takes it by the demise of the ‘Ulama.” Thus, qualified teachers are definitely the keys of knowledge and knowledge can only be acquired from them. This is also something extremely clear and logical. (Al-Muwaafaqaat – vol. 1, pg. 82 – Summarized)