VICTOR KARBEN: THE LIFE AND CUSTOMS OF THE JEWS

Victor Karben (1422-1515), a German Jew, converted to Christianity and was ordained priest in 1486.  In 1504 he wrote a treatise on The Life and Customs of the Jews (De vita et moribus Iudeorum -- an enlarged version was published under the title Opus Aureum). His introduction manifests the fanaticism typical of a convert:

There is no more stubborn and wrong-headed race than the Jews. Nothing in the world can turn them from their traditional faith. If you were to offer someone of the Jewish faith a thousand gulden if he was willing to renounce his faith, you would find it easier to hollow out the hardest rock than convincing him to adopt your views. And it would be a greater miracle! Likewise, if you put a thousand gulden at the foot of a cross and said to one of them, even the poorest man: Look, I will give you these thousand gulden if you fall on your knees when you pick them up from the ground, the man [would rather stay poor] than accept the condition and bow down before the image of the cross. Indeed, even if you threatened a Jew with capital punishment unless he was willing to become a Christian, he would rather be burned at the stake a thousand times than willingly profess the name of Christ once. [And if you suggest to Jews that they might convert in future] they will grow hot and angry beyond belief. All day long they will not be able to show a calm face. Indeed they will remember what you said all their life. Whenever they meet the Christian who proposed such things to them, they will roundly curse him, if not openly, then tacitly….In brief: The Jews are a people more wrong-headed than any other and more inclined to utter curses, indeed a people that tends to be furious and (as I said) vexed and irritated by the very name “Christian”. I speak from experience. For it happened to me too [when I was a Jew and someone] exhorted me to abandon the Jewish error and become a Christian.

But Karben had to admit that Jews who converted were not received with open arms by their Christian brethren. They met with a great deal of prejudice:

Many are of the opinion that it is next to impossible for an ex-Jew to become a good and faithful Christian. And I don’t deny that this is sometimes the case, but conversely it often happens that Jews become very good Christians and remain so to the end of their lives. …A Jew who has recently become a Christian deserves compassion. Getting used to things is always hard, and it is also difficult to forget your past – friends and comrades with whom you spent much time and who were your school fellows, not to speak of the possessions you left behind. …Thus many converted Jews are obliged to beg for their bread…and no one feels sorry for them. On the contrary, people mock them, laugh and point a finger at them, saying: “Look, there goes that baptized Jew!” …Is that not adding insult to injury?