Karl Barth said that everything the Church confesses may be described as "human talk about god". Not all human talk is about god but everything that the Church speaks is human talk and this includes the biblical writings, the creeds and other symbols, prayers, preaching, and virtually everything it expresses. Barth defines "theology" as the Church's self-examination of its human talk about god, and therefore "church dogmatics" is more specifically the Church's scientific self-examination of its human talk about god. Barth begins the Church Dogmatics (CD I/1) with this definition of dogmatics: "As a theological discipline dogmatics is the scientific self-examination of the Christian Church with respect to the content of its distinctive talk about God." [1] The Church has continual need for theology (and dogmatics) in order to self-examine its human talk about god, in order to say the same things today. 

But as it confesses God the Church also confesses both the humanity and the responsibility of its action. It realises that it is exposed to fierce temptation as it speaks of God, and it realises that it must give an account to God for the way in which it speaks. The first and last and decisive answer to this twofold compulsion consists in the fact that it rests content with the grace of the One whose strength is mighty in weakness. But in so doing it recognises and takes up as an active Church the further human task of criticising and revising its speech about God. [2]

The weakness and limitations of human talk means that it is not possible to merely repeat what was said in the past, so the Church is tasked with translating what was said in the past into its human talk today. Since the Church's human talk about god is born from its living witness to Jesus, therefore it is the Church's task alone to revise its human talk about god, and therefore Barth argues that theology (and dogmatics) may only be done by the Church's self-examination of its own human talk, and therefore the Church's human talk about god may not be corrected by anything or anyone outside the Church.  

The Church produces theology in this special and peculiar sense by subjecting itself to self-examination. It puts to itself the question of truth, i.e., it measures its action, its talk about God, against its being as the Church. Thus theology exists in this special and peculiar sense because before it and apart from it there is in the Church talk about God. Theology follows the talk of the Church to the extent that in its question as to the correctness of its utterance it does not measure it by an alien standard but by its own source and object. Theology guides the talk of the Church to the extent that it concretely reminds it that in all circumstances it is fallible human work which in the matter of relevance or irrelevance lies in the balance, and must be obedient to grace if it is to be well done. Theology accompanies the utterance of the Church to the extent that it is itself no more than human “talk about God,” so that with this talk it stands under the judgment that begins at the house of God and lives by the promise given to the Church. [3]

Barth keenly notes the intrinsic weakness of human talk about god (i.e. theology). Human talk is limited by human finitude, and the meaning of human talk is inseparable from its original time, place and culture. Perhaps most Christians are comfortable describing theology as human talk, but there is resistance by American Evangelicals proponents of biblical inerrancy that believe the very words of scriptures are mechanically dictated through the hands of the biblical writers, and various others. However, inerrancy does not solve this problem, because the words in the bible are ultimately human words, and human talk about god in the bible is expressed in human words as they were understood by the biblical authors, and we no longer understand the world in the same way as they once did (such as the sun going around the earth, etc). Even the human talk about god in the witness of the bible must be continually revised and said again today, and this not limited to biblical translation alone, but also demythologizing, internal material criticism, etc. It would be absurd to impose outdated understandings of the world into today (such as done in fundamental's opposition to science). 

The weakness of the Church's human talk about god does not undermine the Church's confessions, but on the contrary it strengthens it. The human talk about god demonstrates that it is revelation of Jesus that matters, and that god has chosen the weakness of human talk to demonstrate the great power of the human witness it explains. As Paul said, "god choose what is foolish to shame the wise" (1 Cor 1:27) and we have "treasures in jars of clay" (1 Cor 4:7).

Sources:

1. Karl Barth, Church Dogmatics: The Doctrine of the Word of God, Volume I, Part 1, trans. G. W. Bromiley, ed. G. W. Bromiley and T. F. Torrance. (London, New York: T&T Clark, 2004), 3.

2. Ibid. 3.

3. Ibid. 4.