Many languages distinguish between inclusive and exclusive first-person plural pronouns (“we”). (Click or tap here to see more details)
The inclusive “we” specifically includes the addressee (“you and I and possibly others”), while the exclusive “we” specifically excludes the addressee (“he/she/they and I, but not you”). This grammatical distinction is called “clusivity.” While Semitic languages such as Hebrew or most Indo-European languages such as Greek or English do not make that distinction, translators of languages with that distinction have to make a choice every time they encounter “we” or a form thereof (in English: “we,” “our,” or “us”).
Velma Pickett and Florence Cowan (in Notes on Translation January 1962, p. 1ff.) recommend the inclusive form (including the writer of the letter and the readers) but SIL International Translation Department (1999) chooses to recommend the exclusive form referring to only Paul himself.