Though Christian churches and Christian individuals have been guilty of antisemitism, the record is better than skeptics and popular history suggest. Whenever churches have stood up for the Jews, the degree of antisemitism in that culture has been far less.
Over the centuries, Christians have been responsible for many crimes and evils committed against Jews, from malicious accusations to forced conversions to expulsions and massacres. While the Church has been culpable for some of the violence, instigated by friars, preachers, and church leaders, there is more to the story.
For example, during the First Crusade, a widespread outbreak of antisemitic massacres occurred when mobs in Germany attacked Jewish communities. They were motivated by a fanaticism and a need to finance their journey to the Holy Land. Although the Crusade had been called by the Pope, the attacks on the Jews were condemned by the entire Church hierarchy. Some bishops offered Jews refuge in surrounding cities, while others sheltered them in their own palaces, though not always successfully. Others bought off the marauding crusaders with silver.
After the First Crusade, Popes Gregory X and Benedict XIII declared that Jews were not enemies of Christians and that their lives and property were to be respected. In his preaching during the Second Crusade, Bernard of Clairvaux explicitly condemned the attacks on the Jews during the First Crusade.
Later, when the Black Death struck Europe, rumors began to circulate that the disease was caused by Jews poisoning the wells of Christians on orders from a Spanish rabbi. Once again, violence against Jews broke out. Hundreds of Jewish communities were destroyed. In the city of Strasbourg, before the plague had even reached the city, 900 Jews were herded into a synagogue that was then burned to the ground.
Again, bishops attempted to stop the violence. Some protected the Jews in their own palaces, and Pope Clement VI issued two papal bulls refuting the idea of well poisoning by pointing out that the Jews were dying of plague just like the Christians. Although the Church in the Middle Ages was guilty of antisemitic acts, particularly at a local level, many secular authorities and mobs also targeted the Jews as convenient scapegoats in times of crisis.