In the same Barth Q and A mentioned in the previous post there is a question about the relationship between Christianity and other religions. Based on the text in Acts 14 where it says that God did not leave the nations without witness or testimony, the student asks Barth whether there is revelation in religions outside of Christianity. Barth's response? "The answer is 'No'" But what then of Acts 14 and these "testimonies" given to the nations?
Barth explains this by drawing a distinction between revelation and what he calls "signs." Certainly, he says, the world is full of signs of God's presence. Paul also talks about this in Acts 17 and in Romans 1. But these signs of God's presence are not revelation, that is, they are not God's self-disclose, His own speech concerning Himself.
Returning to other religions, he notes that in the Bible the other religions surrounding Israel (and later, the Church) are not dealt with as revelation. On the contrary, the relationship between the people of God and other religions is always agonistic (though it must be said that the relationship between the people of God and the people of other religions is not always so). Indeed, Barth summarises the story of Scripture as the fight between God's revelation and what is called religion. "The worst thing in the world," claims Barth, "is religion." One hesitates to conclude that this is mere exaggeration. Indeed, Barth returns to his first answer - there is no revelation in other religions - and adds that one can and must include Christianity in this Nein insofar as Christianity has become a religion. What initially looked like "religious intolerance" from Barth becomes something much more interesting: the call to abolish all religion, including the Christian one.
"God's speaking in the Gospel - now there is revelation over against the whole Christian and non-Christian world!"
The "Thus saith the Lord" is therefore not the word of a pious man, or the theological insight which has arisen form the human heart. It is, for Barth, the Word which is strange and new, graceful and helpful. In other words, revelation is apocalyptic all the way down. If we follow Barth, we might say that the extent to which Christianity fails to conform to this apocalypticism is the extent to which it becomes the worst thing in the world.