The following quote will be an example of how Karl Barth’s understanding of ‘revelation’ works within his own theoretical schematization of things. Bruce McCormack has also developed this in one of his chapters in his book Orthodox And Modern: Studies in the Theology of Karl Barth. The following quote comes from one of McCormack’s former PhD students, David Congdon (from David’s
own published PhD dissertation on Bultmann). Let’s read the quote, then I will close by reflecting on what Congdon has to say.
Jüngel’s central thesis is that, contrary to appearances, Barth’s deployment of the doctrine of the Trinity at the opening of his Kirchliche Dogmatik is not an evasion of hermeneutics but rather a profound engagement with the hermeneutical problem. Barth’s trinitarian theology is, in fact, a form of hermeneutical theology. This is true in two closely related respects. First, “revelation is the self-interpretation [Selbstinterpretation] of this God,” according to Barth. God’s self-revelation in the economic Trinity is an interpretation of the immanent Trinity, and thus it is neither an addition to nor a direct presence of the eternal being of God. God’s being ad extra in the economy of grace corresponds to God’s being ad intra. The event of revelation is therefore the “self-unveiling” (Selbstenthüllung) of the eternal being of God, but it is an unveiling in and through a veil. Or as Barth says elsewhere: “the Deus revelatus is the Deus absconditus.” God is hidden in God’s revelation and not apart from it. That is to say, there is no divine being-in-itself that remains hidden from or alien to the self-giving of God in history, but neither is the self- giving of God one that grants unmediated access to the divine nature. Jüngel glosses this by simply stating that “revelation is that occurrence in which the being of God comes to speech.” Put in hermeneutical terms, “if revelation is the self-interpretation of God, then in it there occurs the fact that God interprets Godself as the one whom God is.”
The context I take this from, in Congdon’s book, is a discussion Congdon is having on the relationship between Barth and Bultmann and their respective projects. He is noting how, as Jüngel underscores, Barth’s and Bultmann’s projects are more complementing rather than disparate. But I simply wanted to lift the quote out of that context in order to give insight into what can sometimes be a source of consternation for many who end up critiquing Barth.
When Barth speaks of ‘revelation’ proper his reference is informed by what Congdon describes above. So revelation proper for Barth is first and bound up in a personal Self-giveness of Godself in the Son, Jesus Christ. In other words, and in brief, revelation for Karl Barth is not what we encounter on paper but in the second Person of the Trinity; so Revelation is ‘Personal’ by definition for Barth.
Can the Bible in this framework and theory of revelation be understood as ‘revelation?’ It can be understood as part of the revelatory event, but Scripture itself can only be thought of as a second part of revelation as it bears witness to and gives way to its reality in Jesus Christ. And in this way the Bible is God’s Bible and not ours; and in this way, then God is able to encounter us as we encounter Him in Jesus Christ through the words of Scripture in a way that allows Him to confront us, and contradict our ways by His. Scripture can do that, as can Proclamation of Scripture as they both give way to their source and reality in Jesus Christ.
The point of what Congdon is highlighting is that Revelation is not something that we can control or grasp; it is something of God’s grace for us (pro nobis) that He gives to us at His direction and determination. I can endorse this concern and desire. And I think understanding Revelation as primarily ‘Personal’ is indeed the way to go when it comes to our thinking here. I also think that this idea, of Barth’s in particular, can constructively be appropriated and developed in a way that fits in quite well with what might be considered a more Traditional (‘pre-critical’) conception of Holy Scripture.
 David Congdon, Demythologizing: Rudolf Bultmann’s Dialectical Theology (Minneapolis: Fortress Press, 2015), 56.