In reading Philip Esler’s position (1998:138-39) in preparation for a future post, he seems understand the idea of “living as a gentile” as dining with gentiles. I think this is correct at least from the context. Yet, this idea is untethered from the oft associated assumption that Peter in eating with was eating the same food. The latter as we have suggested previously is not self-evident from a reading of the text. Thus, the lifestyle of living like a gentile is singularly focused on the issue of association. Gentiles evidently did not have formal barriers which prohibited their associations with others. In contrast, from both the evidence of the New Testament and Second Temple literature it is clear that while there was a wide-ranging perspective on association with Gentiles especially the Diaspora, nonetheless there were boundaries drawn by Israelites—some more conservatively than others—prohibiting intimate association with Gentiles (cf. Acts 10 which suggests that at least some Judeans believed the Law forbade entering Gentile social space). In view of this, Paul's claim that Peter while not living like a Ioudaios--although being a Ioudaios--seems then also to be related to association.
Perhaps a modern analogy would illustrate the point. Amish folk predominately, if not exclusively, reside in the eastern part of the US primarily in Pennsylvania. The have a clear and pronounced identity rooted in a geographical region. Furthermore, it is rare for them to travel outside of the safe confines of their social-cultural space geographically speaking (Remember the old Harrison Ford movie “Witness”). However, it is obvious that on certain occasions they might be required to do so. In these situations it would be clear that they are Amish and they are acting Amishly or living like an Amish person would. Thus the distinctive of the Amish becomes a generic trait. If Paul and Peter were Amish, Paul would be saying to Peter, although you are Amish, you were living like an American, and not like the Amish. Now it is true that the meaning of this charge is not specific and could relate to a number of issues. In our context, as we have established, the focus is on some element of intimate association.
The assertion that Peter is compelling the gentiles to become Ioudaios (Gal 2:14), relates to the consequence of his withdrawal from association and thus implies, as others have noted, the need for circumcision. Still I don't think only circumcision is in view here, but rather the creation of a Ioudaios social space where Ioudaios and gentiles could more freely associate. Thus, I wish to propose that the issue in the Antioch Incident is not what was eaten (traditional view), or how (the manner in which) it was eaten (Nanos’ view), but where it was eaten. I hope to develop this more in a future post.