On the structure of the epistles, from 40 Questions about Interpreting the Bible by Robert L. Plummer:
In structure, ancient letters are quite similar to modern letters or e-mails. New Testament letters usually begin by identifying the sender and receiver (“Paul, an apostle … To the churches in Galatia” [Gal. 1:1-2]). Such a greeting usually is followed by a word of thanksgiving and/or prayer (1 Cor. 1:3-9). One may be tempted to skim quickly through the beginning portions of a New Testament letter, but the careful interpreter will note that ideas introduced at the beginning of a letter often will reappear as significant themes later. For example in Galatians 1:1, Paul emphatically identifies himself as “Paul, an apostle—sent not from men nor by man, but by Jesus Christ and God the Father, who raised him from the dead.” One does not need to read much farther in the letter to discover that the legitimacy of Paul’s apostleship (and thus the apostolic gospel) has been challenged (Gal. 1:10-11). Scholars recognize that the introductions and conclusions of most letters in the New Testament provide hermeneutical “framing brackets” which enable one to see more clearly the work’s emphasis and purposes.
Following the prayer and/or thanksgiving section is the body of the letter. This core sometimes can be divided broadly into theological (Eph. 2:1-3:21) and ethical (Eph. 4:1-6:20) instructions. Other letters are much more difficult to outline of subdivide (e.g., James, 1 John). Letters frequently conclude with a benediction or formalized greetings (Ephesians 6:21-24). Of course, this structure is the general form of a letter, from which there are many possible deviations. For example, the author might not explicitly indentify himself in the greeting (Hebrews), or he may skip the thanksgiving section (Galatians). When an author does deviate from the standard structure, the reader should ask whether there is a reason for such aberrations. In the case of Paul’s letter to the Galatians, it appears that the Galatians’ abandonment of the gospel made an apostolic thanksgiving unthinkable (Gal. 1:6).
This book is slow going for me because there are so many things to look up and check out. Now I’m going to have to examine some of those intros and conclusions to New Testament letters to see if and how they function as hermeneutical framing brackets. Like the first chapter of Ephesians, for instance. What does that tell us about the emphasis and purpose of that book?
Other quotes from 40 Questions about Interpreting the Bible: