What is the halachic approach to the hidden Jews of the Holocaust who were brought up by the Church?
Answer:
According to the halachah, these Jews remains Jews throughout their lifetimes. Even somebody who is entirely unaware of his being Jewish is considered a Jew, and we await his return. In the Talmud, this is known as a "baby who was taken captive among non-Jews"--somebody who was brought up as a non-Jew, but is actually Jewish. For a woman, the person's children will also be considered bona fide Jews, in spite of complete lack of awareness of the fact.