It all began in my 2005 doctoral seminar taught by Mikeal Parsons. The Seminar was on rhetorical criticism and the book of Acts. Dr. Parsons was doing research for his commentary on Acts in the Paideia series which has since been published. We students did a fair amount of the data collection for that commentary.
Our three main sources for ancient rhetoric were Quintilian's Institutio Oratoria, Ps-Cicero's Rhetorica ad Herennium, and the four extant Progymnasmata by Theon, Hermogenes, Apthonius, and Nicolaus. We began the semester by reading Quintilian and Ps-Cicero's works. Anyone who tries to plow through a five loeb volumes in a week knows what fun it can be. After reading these works, I was a thorough skeptic. I did not possibly see how all of these rules meant to instruct ancient orators as to how to compose and deliver a public speech had anything to do with the books of the New Testament.
So, what changed my mind. I suppose you can say that Dr. Parsons gave the students a "gateway drug" in the form of the progymnasmata. The progymnasmata, or preliminary exercises, were lessons given to secondary students in the Greco-Roman education system. After moving beyond primary education, but before entering tertiary education in philosophy or rhetoric, a student would undertake the progymnasmata. The number of exercises vary slightly, but include such things as practice in composing chreiai, maxims, narratives, comparisons, prosopopoiiai, etc.
Each student in our class was given the assignment to summarize one of the preliminary exercises and to find an example of it in the book of Acts. I was given the exercise of syncrisis (comparison) and found a wonderful example of syncrisis in the Stephen episode in Acts 6-8. I will post on that at another time. I found syncrisis not only present in Acts, but also of great use in explaining the text. I was hooked. Ancient rhetoric could be used to enlighten our understanding of New Testament texts.
The subsequent years of Ph.D. study saw me further converted to using rhetorical criticism on the NT, culminating in my Dissertation entitled: Figuring Jesus: The Power of Rhetorical Figures of Speech in the Gospel of Luke.