It is difficult to understand how anybody could have persuaded Peter to stop sharing common meals and the Lord's Supper with Gentile believers. But apparently that is exactly what certain men with connections to James did when they arrived in Antioch. Who were these men? Were they actually sent from James? Or were they members of James's circle in the church but without a direct commission from James? Fortunately for them, Paul cloaks them with anonymity. But he seems to lay on James the responsibility for their disturbance in the church in Antioch.

More important than the question of their identity, however, is the question of their message. What did they say that persuaded Peter to separate from the Gentile believers? The only clue we have is Paul's explanation that Peter separated himself from the Gentiles because he was afraid of those who belonged to the circumcision group (v. 12).

The circumcision group may be another way of referring to those who came from James—namely, Jewish Christians. But why would Peter fear a delegation of Jewish Christians from the Jerusalem church, since he himself was a "pillar" of that church and had already stood up against extremist factions in that church (see Acts 11:1-18; 15:7-11; Gal 2:9)? It seems much better to interpret Paul's reference to the circumcision group in the same way that we interpret his use of the same phrase in the immediate context. Three times in verses 7-9 the NIV translates the same phrase as "the Jews" in contrast to the Gentiles. So the reference to the circumcision group in verse 12 is simply another reference to non-Christian Jews. But still we have to ask why Peter would fear non-Christian Jews when he had been so fearless in his own proclamation of the gospel to them (see Acts 2:14-41; 3:17-26; 4:8-12; 5:29-32). Our answer to that question must be based on historical information outside of the text and some speculation.

It seems that during the late forties and fifties, Jewish Christians in Judea were facing bitter antagonism from Zealot-minded Jews for socializing with Gentiles. The fierce Jewish nationalism rampant in Palestine at that time led to harsh treatment of any Jew who associated with Gentiles. It is likely that the delegation from James simply reported to Peter that his open and unrestricted association with Gentiles in Antioch would cause (or had already caused) the church in Jerusalem to suffer greatly at the hands of the circumcision group, Jewish nationalists.

If Peter expressed his own reason for separating from the Gentiles in Antioch, he may well have voiced his concern about the detrimental effect his table fellowship with Gentiles had on the Jerusalem church's mission to the Jews. When non-Christian Jews in Jerusalem heard that Peter, a prominent church leader, was eating with Gentiles in Antioch, they would not only turn away from the witness of the church but also become actively hostile toward the church for tolerating such a practice. Confronted by these practical concerns for his home church and its mission to the Jews, Peter acted against his own better judgment. He separated himself from the Gentiles.