The study of Paul—more than the study of Jesus—has been and continues to be the arena of discourse where Christians (and recently some Jews) work out their religious identity. Put another way, reading, interpreting and reinterpreting Paul fosters the construction, reconstruction, and sometimes deconstruction of the boundary that marks the distinction between Christianity and Judaism.Since there exists much scholarship on how the history of the interpretation of Paul has been motivated by Christian–Jewish polemic, I will not illustrate that history here. Instead, I wish to highlight two things that distinguish the contemporary debate from previous ones: 1) There is input from the Jewish side—both in terms of content and persons,—which has led to what many think of as a "Jewish" understanding of Paul; and 2) that this Jewish perspective on Paul is not only perceived by some scholars as problematic, wrong, or misguided but as a threat to Christianity itself, thus proving that Christian–Jewish polemic is alive and well in Pauline studies, in spite of recent widespread acknowledgment of Paul's Jewishness!Demonstrating that these two qualities characterize current debate about Paul is not difficult to do. However, by discussing these two aspects of Pauline scholarship, I intend to complicate the notion of religious identity at work in the interpretation of Paul, in an effort to reveal that an essentialist understanding of religious identity underlies the debate about Paul's Jewishness. This kind of essentialism fails to account for the elasticity within religious traditions and the permeability between religious traditions, and thus it greatly exacerbates the problem of Christian–Jewish polemic in the study of Paul. Unless we grasp the flexibility that inheres in religious identity, which includes giving up the notion of essentialism, the study of Paul will continue to be marred by these polemics.