From antiquity to the modern era, anti-Semitism has reared its ugly head despite changing times, locations, language and circumstances. For each outburst of anti-Semitism a reason has been forwarded such as religious, economic, social or racial theorizing. Yet, anti-Semitism has remained consistent despite the changing circumstances and causes assigned. This constancy ought to indicate that a profound cause must exist – this is the thesis this author has pursued in writing this book. The conclusion offered here is that the religious accusation, that of killing Christ for Christians and that of seeking to kill Muhammad for Islam, is foundational to anti-Semitism and that all other causes and reasons identified are inherently religiously based. This thesis is explored by focusing first on the religious context that caused the division between Judaism and Christianity in antiquity. The theoretical grounding offered here is that Christian anti-Semitism was brought on by the co-option of Judaism and the subsequent guilt of such co-option. Similarly, but a lesser degree, Islam has co-opted Judaism and that anti-Semitism is the result of the guilt of such co-option. The author then analyzes several case studies of anti-Semitism including the role of the Messianic idea in promoting anti-Semitism, the hateful rhetoric of St. Chrysostom, an early Church Father, the persuasive strength of the forged Protocols of the Elder of Zion, the Pariah accusation that Jews bring anti-Semitism on themselves, the 2001 Durban conference as an exemplar of Islamist anti-Semitism, and the consistency of the visualization of anti-Semitism via depictions of the diabolic Jew. The book ends by exploring attempts to end anti-Semitism and the efforts of Vatican II in 1965 to admit the Catholic Church’s responsibility over centuries of anti-Semitism.