The “internal” elements of Torah cannot be acquired from books.
Even if they are indeed “the words of the living God,” they cannot address themselves along the precise individual “line” of each reader.
A person can study books on the intimate soul of Torah and drown in them, without ever reaching his Torah and his individual path in the service of God.
He must therefore go to a teacher.
And it is that living, speaking teacher who can address the needs of his student and shape his words according to what the student needs to hear.
–Rabbi Adin Steinsaltz