After some of the comments above, I reviewed my understanding of Barth’s description of God. Again, I’m not that familiar with him, because the more I look the less I like him. I used selections from the CD and some secondary literature.
Barth is strongly opposed to natural theology. We can’t know anything about God in himself. He is completely unknowable. We can only know him in Christ. But what I find weird in this is that he seems to be looking at Christ as an abstract object, not what he actually was, which was (among other things) a teacher. In fact Jesus talked a fair amount about God. Admittedly his talk of Father is to some extent metaphorical, because we don’t know God fully. But still, based on Jesus’ teachings and the OT, we can know at least something about God. In Romans Paul seems to suggest that non-Christians can know something of God through understanding the world, an idea that is impossible for Barth.
I find Barth’s disinterest in historical Jesus work disquieting. In the 1000 volumes of the CD there’s room for plenty of stuff, and so there’s lots of exegesis there. But still, when I read it, I mostly come away with the impression of philosophical rambling. When I do theology I start with the best understanding I can get of what Jesus and the prophets said. (Like many liberals, I find Paul's understanding helpful at times, but not as near the core of my theology.) This is in fact the core of mainline theology, which I think is the current incarnation of traditional liberal theology. (I include in mainline theology a lot of liberal Catholics and evangelicals.) Barth talks in glowing terms about Jesus, but doesn’t actually seem to use him as the primary source of his theology.
Barth faulted liberal theology because it didn’t resist Hitler. This is important, because we have a similar crisis of self-understanding in the US and Europe today. I don’t know what early 20th Cent German liberal theology was like. Maybe it had problems. But today, it’s liberal theology (and also a few evangelicals with similar emphasis), with the emphasis on the teachings of Jesus and the prophets that are most resisting the anti-Christian tendencies of current politics. The people most susceptible to them seem to be those who, like Barth, see Jesus as something to be worshipped, but aren’t as dedicated to reforming theology based on his actual teachings.