Gus diZerega keeps a Pagan blog on Beliefnet. In an entry inspired by a wider debate on abortion and the Bible, he discussed the limitations and dangers of sacred texts. As always, I encourage you to go read the whole thing for yourself.
diZerega basically says that sacred texts have two flaws. The first is that writing freezes a tradition at the point at which it is written down – it becomes an artifact and ceases to evolve with the culture from which it grew. The second is that the reader may think he understands the text when in reality all he has done is to view it through his own preferences and prejudices.
Here’s a good excerpt:
For six years I studied intensely with a Brazilian shaman. Those years were as demanding, maybe more so, than the years I spent getting a Ph.D. at Berkeley. He told us he could tell us everything he knew that could be communicated in words in a weekend. He also said it would be useless information. He was right.
Whether you’re studying shamanism, Wicca, Druidry, practical magic, or anything else, you have to do the work yourself. You have to cast the circles, take the journeys, sit the meditations, cast the spells, and do all the other hands-on work.
As much as I love books, they have their limits.