We've been exploring some things at our Barth reading group lately that are resonating deeply with me and related closely to my studies. D. W. Horstkoettker at flying farther explains his reservations (not strong enough?) about evangelicals' focus on conversion as the central paradigm/narrative for Christian faith. I'd be surprised if DWH doesn't get some feedback from his Lonerganian friends at Marquette out of that blog post. A big part of my project involves looking at conversion in Lonergan, something that is central indeed to his thought (and, in a certain way, I argue, in his experience/history). There's a helpful summary/extension in Happel and Walter, and Donald Gelpi builds on this in Lonergan: here, for example.
Anyway, we ran short of time at the reading group this am, or I would have put forward a suggestion. David has at other times spoken of Barth's method in terms of two concentric circles and a back-and-forth movement between them such that their positions as inside & outside are exchanged. (Putting this in terms of background and foreground might be helpful.) I see this as very helpful applied to conversion.
When I push students in my Distance Learning course on evangelism & discipleship to explore what conversion is (something I do regularly), asking, among other questions, "Is conversion a point or a process?" I often (interestingly, not always) hear them speaking in linear terms, where "sanctification" is the process that continues after the point of "justification," or something similar. I think we would be much better served by 1) defining conversion simply as transformation, and 2) thinking in terms of a metaphor/analogy/model of concentric circles rather than (narrative and spiritual-life-as-journey) linear progression, building on the idea of centered sets in Paul Hiebert, for example (nice summary here).
What Barth's method adds is this: I have come to think of conversion, from my human perspective, in terms of point-within-process, but there is also the flip side where, in Christ, the process of my conversion is completely taken up within the point of Jesus' faithful obedience to his vocation (so I was converted, as Barth & more than one prominent student of his are reported to have said, on a hillside outside Jerusalem about AD 30--even more, I was converted when the Father chose the Son before the foundation of the world).