Winner of the Manfred Lautenschlaeger Award for Theological Promise

Matthew Thiessen offers a nuanced and wide-ranging study of the nature of Jewish thought on Jewishness, circumcision, and conversion. Examining texts from the Hebrew Bible, Second Temple Judaism, and early Christianity, he gives a compelling account of the various forms of Judaism from which the early Christian movement arose.

Beginning with analysis of the Hebrew Bible, Thiessen argues that there is no evidence that circumcision was considered to be a rite of conversion to Israelite religion. In fact, circumcision, particularly the infant circumcision practiced within Israelite and early Jewish society, excluded from the covenant those not properly descended from Abraham. In the Second Temple period, many Jews began to subscribe to a definition of Jewishness that enabled Gentiles to become Jews. Other Jews, such as the author of Jubilees, found this definition problematic, reasserting a strictly genealogical conception of Jewish identity. As a result, some Gentiles who underwent conversion to Judaism in this period faced criticism because of their suspect genealogy.

Thiessen's examination of the way in which Jews in the Second Temple period perceived circumcision and conversion allows a deeper understanding of early Christianity. Contesting Conversion shows that careful attention to a definition of Jewishness that was based on genealogical descent has crucial implications for understanding the variegated nature of early Christian mission to the Gentiles in the first century C.E.

Matthew Thiessen's profile page

Matthew Thiessen is Associate Professor of Religious Studies at McMaster University and the author of Paul and the Gentile Problem (OUP 2016).

"Contesting Conversion addresses an important topic in a fascinating way. It's convincing, makes a highly significant argument cogently, and is extremely well written. The remarkable thing about the book is that Thiessen demonstrates, over and over, that texts that have been understood to support the idea of conversion via circumcision say precisely the opposite. It is not that he has come with an agenda to the texts and discovered that for which he searched, but rather that scholarship till now has done that. Thiessen removes the scales from our eyes."

--Daniel Boyarin, Professor of Near Eastern Studies and Rhetoric, University of California-Berkeley

"This is a significant dissertation, building substantially on previous scholarship to establish the fairly widespread nature of the view that Jewishness was not something to be acquired by circumcision."

--Journal for the Study of the New Testament

"It is a worthwhile read for students of the Hebrew and Christian Bibles, as well as rabbinic literature."

--The Center for Jewish Law

"...refreshing reading...."

--Naomi Koltun-Fromm, Haverford College

"...Thiessen has written an important monograph that should be read by anyone intersted in questions surrounding Israelite and Jewish identity in antiquity...Furthermore, he has offered a fresh and insightful was to make sense of apparent tensions surrounding the question of circumcision in Luke-Acts."

--Council of Centers on Jewish-Christian Relations

"Contesting Conversion argues convincingly, on the basis of a wide range of biblical and post-biblical evidence, that the notion that being a Jew is determined by birth alone, and so cannot be affected by choice, was current in antiquity and alive and well among many Jews in the Second Temple period down to the first century C.E. With regard to circumcision, which many took to be part of a process of conversion, Thiessen argues that many other Jews limited its religious efficacy to male Jewish babies and therefore denied that it could turn a Gentile into a Jew. This book is a welcome and important balance to research into the ethnic vs. religious nature of ancient Jewishness, especially insofar as such research often builds its notions on the basis of rabbinic and Christian universalism."

--Daniel R. Schwartz, Professor of Jewish History, Hebrew University

"This is a fine piece of historical investigation which successfully challenges a scholarly consensus. Exploring the insistence on eight-day circumcision in the Hebrew Bible, some strands of Second Temple Judaism, and Luke-Acts, Thiessen unearths a robustly genealogical conception of Jewish identity that defies modern notions of religion. The result is a highly significant contribution to current debates about conversion, Jewishness and ethnicity in ancient Judaism and early Christianity."

--John M. G. Barclay, Lightfoot Professor of Divinity, Durham University