Several points should be made here. First, Paul’s letters are remarkably dissimilar from typical letters in the ancient world. They don’t look much like the other letters of his day. For example, Paul’s letters tend to be a good bit longer than other epistles from the Greco-Roman world. This might suggest that while the documents that bear Paul’s name were certainly addressed and delivered as letters, there may be something else going on as well.
Second, given this dissimilarity between Paul’s writings and other letters of the period, there are limits to what can be done when his letters are analyzed on the basis of ancient epistolary convention. The beginnings and endings of Paul’s writings can be compared to other ancient epistles, but little is to be gained beyond that.
Third, we know that Paul’s writings were delivered to the various churches to be read aloud when the congregation assembled. Thus, when the original hearers first encountered the Pauline documents, they encountered them as speeches. When added to the evidence considered above, it is entirely plausible to suggest that Paul’s writings are certainly much more than letters. They are really manuscripts of speeches made in the presence of the addressees, speeches that Paul might have made himself were he present with the assembled congregation.
If Paul’s letters are indeed speech manuscripts, then the study of Paul’s letters in light of Greco-Roman oratorical standards is warranted. The letters are persuasive documents that were read like speeches; we should study them as such. Despite the ongoing criticism from some quarters of Pauline studies, rhetorical criticism is worth the time and attention of students of the apostle. Given the many rhetorical studies of Paul available, the question remains: where do we go from here?