Enlightened masters talk about silent transmission of energy/understanding, certain high-powered spiritual texts actually carry that "stamp" of higher consciousness in them, so reading certain books actually raise your consciousness level (i.e. "Power vs. Force", bhagavad gita, bible, etc.). It's kind of like brain-wave entrainment, but consciousness level entrainment?
Understanding a concept intellectually helps pave the way for experiential awareness, so don't throw all your books away
just remember that most of the benefit actually comes from the spiritual consciousness / m-field transmission and not the words themselves, so it is best to seek confirmed sources of spiritual texts (see Truth vs. Falsehood for a complete listing of calibrated spiritual teachers/teachings).
I can personally attest to this, as I've had a bunch of revelations a couple days after picking up a high-level spiritual text, despite not completely understanding the words/concepts in it.