During the first three hundred years of Christianity, when the Jews were not helping the Romans hunt down Christians, the Christians and the jews got along fairly well – as a matter of fact, Christian participation in Jewish festivals was a source of concern for Christian leaders and is mentioned in surviving writings.
After Constantine, Jews and Christians actually lived side by side for 700 years in relative peace, at least in the West – out east there was enough tension between Jew and Christian for the Jews to aid the Zoroastrians in massacring the Christians in Jerusalem during the Byzantine-Persian Wars in the 6th century. There is one case of a high-ranking churchman converting to Judaism and becoming a reknowned apologist for the same without apparently suffering anything harsher than words.
It was only during the 11th century, during the church reform movements, that real trouble began. One basic source seems to have been that the knights were told to act as “vassals of Christ” – since avenging one’s lord was part of a vassal’s duty, and they tended to think in terms of family/clan feuds, there was actually some logic to their thinking, and also explains why the attacks tended to center happen during crusades, when such thinking was at its height. It is worth noting that the clergy did try to stop the attacks at times – just because the warrior/ruling class tended to think a certain way didn’t mean that the churchmen always did.
In conclusion, given that Christian anti-semitism only took off a thousand years after Christ and that the previous millenium was relatively amicable, I find the notion that Christianity required the destruction of Judaism untenable.
