The following two paragraphs are quoted from an article Wolfhart Pannenberg wrote in Christian Century, March 11, 1981, pp. 260-263. In the article Pannenberg outlines his spiritual and theological journey in life, from a non-Christian home to the theological academy. Pannenberg makes a number of interesting observations and reveals some personal insights. In these two paragraphs, Pannenberg outlines his early interaction with Karl Barth at Basle, and the part Barth played in the development of his own thought.
When I began to study theology as well as philosophy at Berlin in 1947, I was not yet certain that I wanted to become a theologian rather than a philosopher. But I was impressed by the Barthians’ emphasis on the sovereignty of God in his revelation, and it seemed self-evident to me that God was to be conceived of as utterly sublime and majestic if there was any God at all, and when I came to Basel in 1950 to study under Karl Barth himself, I was almost convinced of the appropriateness of his approach.
On the other hand, I was troubled by the dualism involved in his revelational positivism. It seemed to me that the truly sovereign God could not be regarded as absent or superfluous in ordinary human experience and philosophical reflection, but that every single reality should prove incomprehensible (at least in its depth) without recourse to God, if he actually was the Creator of the world as Barth thought him to be. Increasingly it seemed to me inconsistent with that assumption that Barth presented God’s revelation as if God had entered a foreign country instead of “his home,” as the Gospel of John tells us (1:11). Therefore, I felt that my philosophy and theology should not be permitted to separate, but that within their unity it should be possible to affirm the awe-inspiring otherness of God even more uncompromisingly than Barth had done, since he returned to reasoning by analogy.
Pannenberg then goes on to describe how he found that unity in the human experience of history, and not just in general world history, but in the history of Israel and the history of Jesus. You can read the whole article here.
PS. One of my favorite quotes from the article is found in the concluding paragraph.
[Christianity] will outlive every ideological regime.
So far so good.