In ascribing the generation of faith to the audibly preached word, the Holy Apostle is tapping into an unmistakable pan-biblical theme of the audibility (over against the visibility) of God's Word. The essential creed of Israel was the Shema ("Hear"), drawn firstly from the Deuteronomic prelude to the "Greatest Commandment":
Hear, O Israel: The Lord our God, the Lord is one. [Deuteronomy vi, 4]Hearing the voice of God is literally all over the Bible. And as it's mentioned, it's mentioned as a truly audible voice.
Reading, on the other hand, cannot boast this same level of biblical significance. While Scripture certainly has something to say about the role of the reading of Scripture, the connection between belief and quiet, private reading is minimal if present at all. There's a good reason for this, I think.
Now faith is the assurance of things hoped for, the conviction of things not seen. [Hebrews i, 1]Hearing and reading are, in terms of mechanics and experience, two different things. While reading requires a significant amount of intentionality behind it, hearing is much more involuntary. Reading is work, labor - the product of much learning, even - but even an infant hears its mother's voice, whether it wants to or not. Much more, reading entails the use of the eyes placed over the text. It, to some extent, reduces the force of the text, placing the reader into somewhat of an evaluative role. Consider the role of vision in the Creation narrative: God "saw" and said it was good.
Whether we intend it or not, whenever we read the Bible (or anything for that matter) we are poised to subject it to a much more interpretive faculty, one which is far more vulnerable to any number of psychological agendas. This is most obvious in that it is in the nature of reading that we must first choose to read, before we begin to read. Any number of motives might underpin our decision to read something, but this element of selection, choosing what to read, what not to read, when to start, when to stop, should have some pretty clear effects. To choose a pretty basic example, someone who chooses never to read the Gospels will likely have a different take on the Torah, or even the Prophets. And it's that choice, that exercise of control or will, that makes reading so much an active exercise. When one reads the Bible to himself, he is as much choosing his own adventure as is the author "behind the text." Most dangerously, with the text so far below the reader, so subject to his psyche, one may create with incredible ease an emotive distance between himself and the text that wholly objectifies, rendering it personally meaningless. That there are agnostic Bible scholars should be sure proof of this.
Hearing, on the other hand, is different. While there are some ways in which one "intervenes" in the act of hearing, on the whole, the action is far more passive. It is precisely this weakness, this passivity, that proves aural faculties so virtuous for stirring up faith in the hearts of God's people. For in choosing to hear the word of God rather than to read it (that is, rather than to scrutinize it - or at the very least, to scrutinize about it), we are choosing to employ our bodies as best we can to receive the word of God in full passivity, full submission, making ourselves wholly vulnerable to the will of the Father.
The most prevalent temptation here, though, is to smooth out these differences, overlooking the fact that hearing is not precisely the same thing as seeing/reading, assuming instead that, one way or another, they both convey the same information. But this is wrong. While we should never affirm something as dully simplistic as "the medium is the message," we should certainly realize that the message can never be wholly separated from it's medium. The various media we employ to communicate communicate all sorts of things beyond the raw information we intend to convey. For example, a type-written note conveys an inarticulable sense of formality that a note scribbled in pencil never can.
It is at this point we should realize how, to choose a masterful case-in-point, the printing revolution that has allowed present day Christians to have multiple copies of the Bible per person, has had a great deal more to do with our ideas about Scripture reading than any biblical theology of Scripture. That is to say, Gutenberg's printing press inadvertently stole the Bible from us. We should not be so self-confident to think that technological progress cannot yield ideological regress.
Obviously, I'm not opposed to reading the Bible. I think there's some real value to it and I do it myself quite a bit. I go to something like three bible studies a week. But I don't think it's commanded in Scripture and I would never chasten a fellow believer for failing to do so. The way I apply all this practically is by frequently leaving my Bible closed during a worship service, and spending time, instead, on listening. That after all, is what we're told to do.