Douglas Groothius:

The medium of communication matters since it always shapes the messages it carries, and these mediated messages shape us. A novel and a television series based on a novel differ in crucial ways, for example. Therefore, any medium should be exegeted to determine its nature, function, and structure. Only in this way can we ascertain what it does well, what it cannot do, and what it does poorly. This is what Marshall McLuhan meant by his hyperbolic slogan, “the medium is the message.” Taking his cue from the discussion of idolatry in Psalm 115, McLuhan also remarked that, “We become what we behold” (see also Ps. 1). When we become habituated to a particular form of communication, our mentalities and sensibilities bear its mark. . . .

When the image dominates the word, rational discourse ebbs. We are attracted to the incandescent screen just as medievals were attracted to stain glass windows; as McLuhan noted, the light comes through them as opposed to light being shown on them (as with books and photographs and other objects in the physical world). . . .

When the image overwhelms and subjugates the word, the ability to think, write, and communicate in a linear and logical fashion is undermined. Television’s images have their immediate effect on us, but that effect is seldom to cause us to pursue their truth or falsity. Television’s images are usually shorn of their overall context and meaning, and are reduced to factoids (at best). Ideas located within a historical and logical setting are replaced by impressions, emotions, and stimulations. While images communicate narrative stories and quantitative information well (such as graphs and charts), words are required for more linear and logical communication. Propositions and beliefs can be true or false; images in themselves do not have truth value. The persuasiveness of the image on television led media theorist Tony Schwartz to claim that truth is now an outmoded concept, since it belongs to a time when print communication was dominant.

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The triumph of the televised image over the word contributes to the depthlessness of postmodern sensibilities. Reality becomes the image, whether or not that image corresponds to any objective state of affairs — and we are not challenged to engage in this analysis. ... As a consequence of such nonactivity, truth suffers, and truthfulness is downplayed if not ignored. Joshua Meyrowitch, a professor of communication, complains that his students “tend to have an image-based standard of truth. If I ask, ‘What evidence supports your view or contradicts it?’ they look at me as if I came from another planet.” This is because “It’s very foreign to them to think in terms of truth, logic, consistency and evidence. “Such oblivion exists not only in the case of media students, but is true of culture at large, as cultural critic Kenneth Myers stresses: “A culture that is rooted more in images than in words will find it increasingly difficult to sustain any broad commitment to any truth, since truth is an abstraction requiring language.” . . .

Muggeridge commented that when the Israelites worshipped the golden calf instead of waiting for the Word from Moses, they attempted to televise (or make visible) God. Biblically speaking, God commands that we not make graven images or attempt to televise the invisible. In the beginning was the Word, not the image (John 1:1). God gave us a book, and spoken word from incarnate preachers. When, in any culture, written language is marginalized by television, biblical truth begins to lose its vibrancy. Christians must restore the primacy and power of the Word as an antidote to truth decay by television.

From "People of the Word in a Culture of Images"