It is important to remind ourselves that Galatians comes down to us as a letter and not as a theological tract or treatise. For it is the letter form which makes the whole document so personal and which gives its appeal such an emotive quality. Paul is addressing those he had come to know during his own visits to Galatia. In other words, the rhetoric of the document is not directed at an impersonal audience but to individuals he remembered and no doubt could have named. Moreover the relationship was one of mutual benefit. They had given him a warm and supportive welcome when he first arrived, apparently in some physical discomfort or worse (4.13–15). And they in turn had received the blessing of Paul's message, having been converted through his own ministry. The letter, then, was a means of renewing old relationships, a substitute for a personal presence which distance made impossible (4.20). It was a personal message delivered by letter because Paul perceived the need as urgent and because, presumably, his own circumstances made a visit in person impracticable.

The main bulk of the theology lies, of course, in the body of the letter. Comparison with other letters of the time provides a strong indication of just how freely Paul adapted the letter form to suit his own purposes, particularly in the solid theological character of the body of his letters.