Segal uses this distinction to explain the struggle that Paul had with opponents in his letters. While Segal finds that conversions did occur in the first century, Paul's problems started in earnest when he tried to reconcile the observant and non-observant wings of the church. Segal's thesis is that Jews supported the idea of converting Gentiles, but were repulsed by non-observnt Gentiles and observant Jews worshipping TOGETHER.
The weakness of this work in its tendency to describe Paul as a kind of first-century religious quester. A position that does not fit with the self-description of the man in his letters. It is also a bit unnecessarily long, especially in the first 70 pages or so, when Segal spends much space describing the religious attitudes of various religions in the first century. Much of this does not apply to his larger arguement, and provides detail for the sake of detail. It is, however, an excellent examination of the sociological implications of Paul and his work. A worthy read for any student of Paul and his literature.
Doug Ward