Has any relationship between world faiths been more fraught with ambivalence than that between Christians and Jews? Christian identity contains within it a unique challenge, in that it both rests on, and derives from, Jewish identity. As a result, Judaism simultaneously grounds and undermines Christian life, pushing Christianity toward two opposite claims: either to supersede Judaism, or to negate it. The first claim implies an appropriation of Jewish identity, the second a repudiation. The first involves Christians in the uncritical presumption of Judeo-Christianity-the idea that the distinction of Jewishness disappears in its foretelling of Christianity. The second involves Christians in a heresy as old as Marcion and as recent as Nazism, the tempting and toxic vision of Christianity as utterly Judenfrei.

With his new book, Christ Killers, Jeremy Cohen, professor of European Jewish history at Tel Aviv University, isolates a crucial piece of this self-divide within Christian identity-the story that all Jews crucified Christ-and traces its impact on the history of the church, the Jewish people, and Western culture generally. The book helps explain how Jewishness, so intrinsic to early Christian identity, later became so separate from it. Building on widely accepted biblical criticism, Cohen wisely brackets the question of who bears the brunt of historical (as opposed to theological) responsibility for the Crucifixion-a question he suspects will never be satisfactorily answered. Of greater interest to him is the way the Gospel writers chose to tell the story of their savior’s death, heavily implicating Jesus’ Jewish contemporaries.

Cohen is in good scholarly company when he suggests that these implications (and indeed imprecations, as in the notorious cry that Matthew 27:25 assigns the Jewish crowd: “His blood be on us and on our children!”) reflect a high pitch of intra-Jewish strife, as messianic Jews competed with nonmessianic Jews for rights to prescribe the self-understanding of the Jewish people. Cohen might have added to his bibliography Luke Timothy Johnson’s masterly but provocative essay “The New Testament’s Anti-Jewish Slander and the Conventions of Ancient Polemic” (Journal of Biblical Literature, Fall 1989). Johnson argues that the severity of anti-Jewish polemic in the Gospels conforms to ancient rhetorical practices of dispute and condemnation among contending philosophical sects. Such an understanding blunts the bite of the polemic and hopefully restricts the harmful effects it might still have; it cannot, of course, undo the damage already done. Over time, externalized and absorbed into nascent Christianity, the story took on a life of its own. Christ Killers illustrates the old Platonic dictum that we should beware of the stories we tell, since stories shape human thought and action. As Cohen ably demonstrates, a major consequence of telling this particular story has been centuries of suffering for the Jewish people.

The book comprises three parts. Drawing on biblical and patristic writings, especially Melito of Sardis, Cohen first examines the origins of the story that Jews bore (and continue to bear) responsibility for Jesus’ death. He then traces the story’s harmful impact on Jews through the Middle Ages and modern times, and concludes by spotlighting the theme in discrete works of art, theater, and film, including the ongoing Oberammergau Passion play (next scheduled for 2010) and the infamous Mel Gibson film, The Passion of the Christ.

Unsurprisingly, since Cohen is himself a medievalist (a previous book, The Friars and the Jews: The Evolution of Medieval Anti-Judaism, won the Jewish National Book Award in 1983), the middle part of his essay is the longest and most engaging. Yet, a specialist’s deep immersion in his particular area doesn’t always serve a work of much broader scope. For example, Cohen’s assertion that “from the end of the eleventh century onward, Catholic Christianity focused with increasing intensity on the humanity of Christ,” and that this humanity “found its most profound expression in the very real pain and suffering of Jesus’ Passion,” surely applies only up to the end of the Middle Ages, for with the Renaissance and Erasmus, the humanity of Christ finds its salient Catholic expression in the ethics, not the suffering, of Jesus.

But these are small oversights. Within the bounds of the Middle Ages, Cohen is superb, and it is here that he offers one of his most interesting theses: that the harmfulness of the Christ-killer trope varied according to whether the killing was understood to have been done knowingly or unknowingly. Augustine, who thought the Jews innocent of knowing Christ’s divinity, taught that they filled a necessary role in Christian society as bearers of a book that, unbeknownst to themselves, foretold the coming of Christ. (Cohen omits one of the more endearing of Augustine’s names for this office: “slave librarian.”) By the late Middle Ages, however, theologians, including Thomas Aquinas, taught that the Jews knowingly executed their savior-an interpretation that effectively demonized them and rendered them prey to the savageries of the Crusades and the Inquisition.

Cohen is a historian, and while that role enlivens the story he recounts here (often passionately, with italics and exclamation points), it also limits it. Take, for instance, the symbol of the Cross. Contextualized by Christian theology, rather than solely by Christian history, the Cross bears a multiplicity of meanings that Cohen only tangentially cites, intent as he is on assimilating it into the trope of Christ-killing Jews. One central meaning (to which, as Cohen notes, even the Middle Ages attested) is that all who behold the Crucifixion bear responsibility for it-and most especially Christians, who have it most continuously in view. On this reading, the viewer is the Christ-killer, and Jews, who traditionally shun the image, fairly disappear from the incriminating gaze. Christian communities-surely among Cohen’s intended audience-would more readily hear his important points about the Christ-killer myth if he evidenced more awareness of readings of the Cross that do not expressly and exclusively implicate Judaism.

Still, Judaism’s challenge to Christianity remains; and Cohen’s book, insofar as it addresses Christians, is a call to alarm. Its chapter on Vatican II explores the ambiguities of that signal council’s banishment of the Christ-killer trope from the church’s understanding of the Jewish people. Cohen laments that, while many Catholics during those heady days in the Catholic Church understood the catastrophic import of all Christian teachings that demonized Jews (including the then editor of Commonweal, James O’Gara), the council did not take full responsibility for the presence of these teachings in the New Testament itself. Cohen looks to liberal Bible commentators such as John Dominic Crossan-who, by taking the gospel to be much more story than history, open it up to a critique of biblical anti-Semitism-to focus the church’s attention on its own perhaps unwitting perpetuations of the Jewish Christ-killer myth.

The need is urgent, as the myth has spread beyond the Western church to Arab cultures, where it adds even more fuel to raging ethnic and political fires. I suspect this ongoing historic need will not be met fully until a theological challenge that precedes it is resolved. Christianity must come to terms with the Jewishness in its midst-and do so in a way that seeks not to extinguish or supersede it, but to recognize and embrace it.