I've been reading through the Barth/Bultmann correspondence this morning, and came across the below in one of the appendices. Given that I posted about Hans Frei's understanding of heresy on Monday, I figured I should throw this up as well.
To set the stage, Barth is writing in response to a letter from a bishop asking whether Barth considers Bultmann's views on the resurrection, etc, to be dangerous things. The bishop was prodded to seek an answer to such questions by a letter he received from a pastor who had heard Bultmann lecture and refer to "the legend of the empty tomb" and the "marvel of the resurrection." This pastor hoped to initiate the founding of specifically ecclesiastical institutions for the training of clergy - a move which puts one in mind of a chapter from the church's history in the United States.
While Barth does not hide his misgivings about Bultmann in his letter, he does note that there are perfectly acceptable (to his mind) ways of interpreting these statements, and thus he defends Bultmann to some degree. But, here is what he has to say about "heresy" (notice the quotation marks in Barth's text - it seems to me that he has his tongue edging over toward his cheek on that point; bold is mine):
In the disposition and direction indicated by the letter of Pastor Bruns no controversy should be initiated between the church and the theology of Rudolf Bultmann. The harm that would be done thereby would be incomparably greater than what is to be expected from Bultmann's writings and teaching—whose original purpose and positive qualities should not be forgotten for a moment because of his “heresy.” A contesting of heresy which misses the essential point, well-meaning though it may be, has always been more dangerous to the church than the heresy in question. The existence of the extreme critic in Marburg, who is himself the occasion of so much criticism, and who works in a rather humorless place that seems to find pleasure in criticizing, will certainly not ruin the Evangelical Church in Germany... I even conjecture that the existence of a “heretic” like Bultmann, who is so superior to most of his accusers in knowledge, seriousness, and depth, might be indirectly salutary to the church as “a pike is in a pond of carp.” On the other hand, the rise of a clerical group that hands out censures or doctrinal judgments with neither true vision nor reflection, no matter how orthodox it might aim to be, can only bring about destruction.