IV. The Unity of the Letter
The question of unity is the major critical issue. Some scholars say the letter is fragmented into distinct sections that originally may have been as many as three separate letters later joined together. Specifically, 1:1-3:1; 3:2-4:1; and 4:10-20 have been questioned (see Beare, 1-5).
Most scholars, while noting the fact of some lack of coherence, hold to the unity of the letter. Lightfoot suggests that Paul may have been interrupted while writing. Others point out that the lack of unity is not inconsistent with the letter's intense personal nature. It is best to let the letter stand as is.