One of the most helpful ways of tracing the flow of thought in biblical passages is now a whole lot easier thanks to BibleArc.com.
"Arcing" is valuable because it forces you to think about and articulate your understanding of the relationship between each unit of thought in a passage. When you are finished, you can see at a glance the major emphases of the passage, and how the various parts fit together.
Sometimes arcing exposes new interpretive possibilities and unexplored exegetical issues:
The one major drawback of arcing is that it was time consuming to write out the text, draw, erase, and redraw each arc by hand. All that has changed with the arcing tool provided by BibleArc.com. The tool automatically inserts the Greek or Hebrew text or translation of your choice, and dividing a passage into units of thought and drawing and erasing arcs is the work of a mouse click or two. Now instead of spending time writing out a passage you can concentrate on the work of analysis.
I was taught arcing in 1993 by Bruce Fisk. When I went on to TEDS for my MA, I was introduced to it again by D.A. Carson. When I began teaching Greek Exegesis, I created a replica to replace the tattered hand-out I had been using (download it here).
The method apparently originated with Daniel P. Fuller, professor emeritus of hermeneutics at Fuller Seminary, and son of the seminary's founder, Charles Fuller. Fuller's student, Thomas Schreiner, introduced the methodology in Interpreting the Pauline Epistles (Baker, 1990). It has been championed more recently by another of Fuller's students, John Piper. (See the video on the home page of BibleArc.com.)