The writings of  the Divines are nothing else but a preaching of the gospel to the eye, as the voice preaches it to the ear.

Vocal preaching has the pre-eminence in moving the affections, whenever it is applied to the condition of the hearts in the congregation which hears it.  This way the milk comes warmest from the breast.

But books have the advantage in many other respects:

• You may read an able preacher when you have only an average one to hear.  Every congregation cannot hear the most judicious or powerful preachers, but every single person may read the books of the most powerful and judicious.
• Preachers may be silenced or banished, while books may still be at hand.
• Books may be kept at a smaller charge than preachers.
• We may choose books that address the very subject which we desire to hear about; but we cannot choose what subject the preacher shall treat us.
• Books we may have at hand every day and hour, when we can have sermons but seldom and at set times.
• If sermons are forgotten, they are gone. But a book we may read over and over, till we remember it. And if we forget it, we may again peruse it at our pleasure, or at our leisure.

So, good books are a very great blessing to the world.  The Holy Ghost chose writing to preserve His doctrine and laws for the Church, knowing how easy and surely it is a way of keeping it safe for all generations, in comparison with mere verbal traditions.

~ adapted from the Works of Richard Baxter