People consider themselves to be knowledgeable because they have read books and well informed about the subject. But all these accumulated knowledge is not wisdom. One can’t get non-dual wisdom from accumulating knowledge.
Whether the knowledge accumulated are of the scriptures or something from more recently published books are mere pointers to truth but not wisdom. First, whether one is aware
of it or not, as he reads he is imposing his own cultural conditioning, biases, experiences, and prior knowledge onto what he is reading; this is how his thinking faculty works. He “makes sense" of new things by associating them with things he already knows.
Most of the time, this is useful. But if the "new thing" is utterly different from anything one has been exposed to before, he is almost certain to distort it to make it fit into pre-existing conceptual boxes. So much of knowledge is about changing perspective, but that's hard to do when he is twisting the knowledge around to fit the perspectives he is already has.
As one goes on digging mentally and on more things will be revealed to him through inner revelation, which makes him get A firm conviction of what is what. --FORMLESS PATH