Why does Paul bother to say this when his main thrust is not to show the lack of contact between himself and the other believers, but between himself and the apostles? It is because in his mind the churches of Judea were linked to the apostles, since Judea had been the location of their evangelistic efforts (Acts 9:31-32; 10:37; 11:1). Paul as a persecutor of Christians had been most active in Jerusalem, not in Judea as a whole. In fact the Christians he had persecuted in Jerusalem had fled to Judea to escape persecution (Acts 8:1-2). Luke makes the same distinction there between Jerusalem and Judea that Paul does in Galatians 1:18-22. Although Jerusalem was in Judea; Paul evidently means to distinguish between Jerusalem and the rest of Judea in verse 22.