Of the four roots of anti-Semitism, religious anti-Semitism has the longest history in Western Christian societies. Religious anti-Semitism encompasses hostility that stems from the Jewish people's refusal to abandon their religious beliefs and practices and, specifically within Christian societies, from the accusation of Jewish collective responsibility for the death of Jesus Christ. By the eighteenth century, the religious root would expand to include the French Enlightenment critique that Judaism was responsible for the antiprogressive and exclusionist characters of its followers.

Official Christian antipathy toward Judaism began to gather steam within one hundred years of the death of Christ. Christian bitterness may have stemmed largely from the new religion's competition with Judaism for a following. The competition between the two religions was unlike that between quite dissimilar religions – such as Buddhism and Christianity, or Hinduism and Christianity – for Jesus Christ had been a Jew, and Christianity saw itself replacing Judaism as the inheritor of God's covenant with Abraham. Because only the Jewish people can claim that the Christian Savior was one of its own, the relationship between Judaism and Christianity is special. The strong desire for Christian self-affirmation and Christian disconfirmation of Judaism, especially during the church's formative years, may help to explain its unique anti-Judaism. As both Rubenstein and Langmuir cogently remark, the greatest threat to the Christian belief system was the denial of Jesus by the Jews.