"Jesus Christ, as he is attested for us in Holy Scripture, is the one Word of God which we have to hear and which we have to trust and obey in life and death."
And with it the corollary negative statement:
"We reject the false doctrine, as though the church could and would have to acknowledge as a source of its proclamation, apart from and alongside this one Word of God, still other events and powers, figures and truths, as God's revelation."
The power of this statement against the attempted Nazi takeover of the Protestant churches of Germany is obvious. For Barth, however, this is not just a defensive statement. Throughout the Church Dogmatics, this is the one theme to which everything is related. Just as the apostles asserted that there is no other name in which salvation is found, so Barth insisted that there is no other name in which (normative) revelation is found. God is to be sought only in Jesus Christ, which concretely means only in the prophetic and apostolic testimony to Jesus Christ which makes up the Christian Scriptures.
Barth's insistence on this point led him to recast several major areas of theology. The doctrine of Scripture is shaped by it, since even Scripture itself must bow to the Lordship of Jesus - it is only the word of God in a secondary sense, and in so far as it bears God's authorised witness to his Son. The doctrine of election is broken down and remade around a Christological centre - Jesus is the elect one, and the reprobate one in our place. Theological anthropology takes as its text, not humanity in general or even as created, but the man Jesus Christ.
Incidentally, it baffles me that a theologian like John Frame could write that "...Barth and Bultmann argued that though God still exists, His activity cannot be identified in space and time, that it affects all places equally and none in particular. Thus, in effect, there is no revelation..." I wonder whether he has read any Barth.
Whilst Barth's opponents on the scholastic end of Reformed Protestantism derided him as some sort of Christomonist, Barth himself felt that this was the theological battle of the 20th Century (and since it has not yet been won, I suppose it will be the battle of the 21st Century as well) - where the Reformation-era church was called to fight for the sole efficacy of Christ's work in salvation against a creeping semi-Pelagianism, the modern church is called to fight for the sole efficacy of Christ's work in revelation against a creeping natural theology. The latter is, for Barth, always idolatry, and practically paves the way for the German Christians.
I love Barth for this emphasis. That is not to say it does not get him into trouble - not, I think, in the places evangelicals often assume he gets into trouble (Scripture, election) but in slightly more obscure places. His doctrine of angels and demons is radically different from that of the rest of the church, mainly because he refuses to interpret certain verses about fallen angels in what appears to be the straightforward way - for no other reason that this would seem to leave them somewhat unrelated to Christology. What is happening here is that we are losing the "as attested in Holy Scripture" part of Barmen, and assuming a Christ who does not quite fit that testimony. Nevertheless, this weakness is the flip-side of a tremendous strength, which leaves me feeling that reading Barth I am being pointed again and again, and in a much more direct way than in most other theological works of this complexity and size, to the Lord Jesus.
And for that, I am thankful.