A History of Christianity: The First Three Thousand Years

by Diarmaid MacCulloch

Augustine of Hippo had declared that God had allowed the Jews to survive all the disasters in their history to act as a sign and a warning to Christians. They should therefore be allowed to continue their community life within the Christian world, although without the full privileges of citizenship which Christians enjoyed: God only intended them to be converted en masse when he chose to bring the world to an end. So Jews continued to be the only non-Christian community formally tolerated in the Christian West, but their position was always fragile, and they were excluded from positions of power or mainstream wealth-creating activities. One result was that a significant number turned to moneylending at interest (usury), an activity which, thanks to half-understood prohibitions in the Tanakh, the Church prohibited to Christians. That trade could bring wealth to Jews, but certainly not popularity.