This is from Frame’s chapter on epistemology in his book on the doctrine of God:
More recent thinkers have also appealed to divine transcendence to show that there is something inappropriate about using human language to refer to God. Such claims often have the force of relativizing the truth of all human language about God, including that of Scripture. For example, Karl Barth says:
“God does not belong to the world. Therefore he does not belong to the series of objects for which we have categories and words by means of which we draw the attention of others to them, and bring them into relation with them. Of God it is impossible to speak, because he is neither a natural nor a spiritual object. If we speak of him, we are no longer speaking of him.”*
How, then, can we preach or teach about God? Ott paraphrases Barth’s answer:
“Barth’s solution is that in our own strength and with our own possibilities it is impossible for us us to speak of God. The fact that we speak about him and yet are unable to do so is a fault which God himself forgives, and in doing so he takes our human words and concepts which in themselves are inappropriate and transforms them into a fitting witness to himself.”**
How can they be a fitting witness if they are in themselves appropriate? If “God is good” is inappropriate in itself, what does God do to that phrase–or to us–to make it appropriate? This claim should be related to Barth’s well-known view that revelation is not the communication of propositions or information, but a nonpropositional communication of God himself to us. What is communicated is God’s power, love, and salvation, but not verbal content. Like Aquinas, Barth is not entirely consistent in this view. One wonders what value there is in the many volumes of of Barth’s Church Dogmatics if indeed all its words and sentences are inappropriate. Would it not be less expensive to seek God’s will in a cheaper, but also inappropriate source, such as a telephone directory?
Certainly God’s grace plays an important role in our preaching and teaching. But it does not change the meanings of our words from false to true. It often moves us to abandon false words and substitute words that are true to God’s Word. But nothing in Scripture suggests that God takes a false sentence and makes it true by sheer grace.
Nor does Scripture ever suggest that human words are in some general sense inappropriate to refer to God. Rather, it claims over and over that its own words, and other words that truly convey its content, are entirely appropriate and should never be disobeyed or disbelieved. It is wrong, therefore, to say that human language is defective as an instrument of divine-human communication.
However, analogy does play an important role in our knowledge of God. There are a number of areas of theology where the divine mystery is so impenetrable that we can only get a small glimpse of the truth. Often that glimpse comes through analogies. We have already seen in our discussions of human responsibility and the problem of evil that some theological problems elude our attempts at precise solutions. In those areas, I have suggested some analogies (the storyteller model, the greater-good defense) that point in the direction of better understanding, but do not remove all difficulty. We shall see that the doctrine of creation ex nihilo and the doctrine of the Trinity also resist our attempts at precise, literal formulation. But theology has accepted ex nihilo (a phrase very difficult to define) as a suitable analogy of creation. And Scripture itself provides the names Father, Son, and Spirit, as suitable analogies for the Trinitarian persons.
John Frame, The Doctrine of God, 209-11
*Karl Barth, Church Dogmatics, 1.2, 750
**Heinrich Ott, God, 99-100