Novenson presents a comprehensive study on the depiction of Judaism in early Christianity, particularly through Paul's letters. He notes the concept of "Paul and Judaism" has been profoundly studied, despite "Judaism" appearing only twice in all of Paul's works. He debates the modern English interpretation of 'Judaism' differs from Paul's usage, focusing on the implications of this in Galatians. Exploring historical interpretations, Novenson recognizes that Galatians is often perceived as Paul's diatribe against Judaism. However, scholarly interpretations vary from Marcion's notion of a clash between two gods, to Bultmann's view of Paul’s condemnation of Jewish striving for righteousness, to Martyn's perspective of Judaism as excluded from salvation. Novenson also examines Steve Mason's interpretation of Ἰουδαϊσμός (Judaism). Mason suggests that the term refers to the adoption of Jewish customs by non-Jews rather than the religious practices of the Jews themselves. Although Novenson doesn't debate the distinction between ethnicity and religion, he leaves open the question of whether Mason's revisionist understanding is historically accurate. Besides, Novenson challenges Mason's interpretation, maintaining that "to judaize" signifies non-Jews adopting Jewish customs, while "Ἰουδαϊσμός" indicates Jews' own pursuit and promotion of their traditions. He suggests that these terms' etymology and usage illustrate the dynamic nature of language, where meaning can shift based on context and time period. Novenson theorizes that the term "Judaism", originating from the second century BCE Maccabean Revolt, reflects not an ancestral religion but a political cause to defend Jewish customs. He suggests this term emerged in response to Hellenization during the Antiochene persecution, where following Jewish traditions became a political act that required a term. Additionally, in Paul’s Epistle to the Galatians, Novenson interprets the term Ἰουδαϊσμός as reflecting a politically active group of Jews rather than the broad spectrum of Jewish religion and culture. He disputes that Paul's past commitment to Jewish traditions, depicted in Galatians 1:13-14, reflects his involvement in a conservative Jewish faction, not general Jewish religiosity. Finally, Novenson suggests that Paul's letters, while limited in providing a complete Christian theological perspective on Judaism, interpret Judaism mainly in relation to Paul's mission to convert Gentiles and privilege faith over Jewish law and customs.