Proselytism and conversion are ancient phenomenon, as old as the Jewish people. Throughout the generations, the approach to and treatment of converts has varied depending on the attitudes, feelings, and political state of the Jews at each point in history.
The first proselytizer, according to Jewish tradition, was Abraham, who with his wife, Sarah, would approach people, invite them into his house, feed them and give them to drink, befriend them, draw them closer and convert them, and bring them under the wings of the Divine Presence (Midrash Genesis Rabbah). The archetypical Jewish convert is the biblical character, Ruth. Ruth was married to a Jew, and after his death she remained attached to his family and his nation. Her declaration of loyalty, "Wherever you go, I shall go, and where you lodge, I will lodge; your people shall be my people, and your God my God; where you die, I will die, and there will I be buried" (Ruth 1:16-17), became a paradigm of faithfulness to the Jewish people, in life and death. Her declaration included both an expression of attachment and commitment to the Jewish nation (Your people shall be my people), as well as to the Jewish religion (Your God is my God). The Bible also recounts two instances of mass conversion during the time of King David and Queen Esther.
There is historical evidence of a strong attraction to Judaism and the Jewish people in the Persian empire, during the Hellenistic period, and in particular during the Roman period (approximately the 1st century C.E.). Many Persian and Roman citizens renounced idolatry, began to observe Shabbat and certain fundamentals of Kashrut, and were known as 'God fearing people'. Some of them were even circumcised and thus fully accepted into Jewish society. Scholars estimate that the number of those who identified with the Jewish community approached 10 million people, 10% of the ancient world that is known to us. An additional 5% were 'Sabbath observing non Jews'.
The conversion process was formalized and institutionalized during the rabbinic period. A legal-religious process was instituted, which included an appearance before the religious court, circumcision for males, ritual immersion, and the offering of a sacrifice. Converts were readily accepted, and a special prayer was even added to the regular prayer to be recited thrice daily, blessing the converts. Various traditional sources call the Jewish people a 'nation of converts', a nation whose ancestors all converted upon receiving the Torah at Sinai, and who has throughout the generations constantly attracted additional converts. Included among the famous converts of the Roman period are: King Herod, Queen Helena and her sons, and many others who ultimately became great Torah scholars. With the defeat of the Bar Kochba revolt, interest in conversion declined. Once Christianity became the official state religion in the Roman Empire in the beginning of the 4th century C.E., conversion to Judaism was prohibited by law.
During the Middle Ages, conversion became increasingly less common. Most Jewish communities insisted to a certain extent on separating themselves from the societies in which they existed. Christian authorities in Europe persecuted any communities suspected of proselytization and even sentenced converts to death. Countries under Islamic rule, by contrast, maintained a neutral attitude towards conversion.
Since the Emancipation and the onset of the modern era, and in particular during the 20th century, diverse views have been articulated regarding conversion. Some view proselytization as the supreme Jewish national - religious mission today, the solution to the problem of assimilation, and a means to guarantee the Jewish nature of the Jewish state and the Jewish people. This approach argues that the Jewish people should embrace potential converts and seek to find creative solutions to conversion issues. There are others, though, who consider a non-rigorous process of conversion a threat to the distinctive nature of the Jewish people and to the Jewish religion that has been preserved over thousands of years.
