1) I suggest that the real number of Jews in the world may be a lot more than we think. I have a source for this from the Brisker Rav on the Chumash in Parshas Vayechi, Bereshis 48:16. He explains the passage in Yeshayahu 66:18-21, which appears in the Haftarah when Rosh Chodesh falls on Shabbos. The Navi Yeshayahu tells us how the nations of the world will come to Yerushalayim when Mashi'ach comes. There is a verse there (66:21) which reads,

"And I will also take from them, for Kohanim and Leviyim, said Hash-m."

This suggests that among those who return from the nations of the world will also be Kohanim and Leviyim. This already indicates that people who seemed to have assimilated among the nations will be discovered to be Jewish. This itself is surprising enough, but how is it possible that not only will they be ordinary Jews, but they will in fact even be Kohanim and Leviyim?

2) The Brisker Rav writes that one would think that the children could remain Jewish, even though they assimilated, only if there was an uninterrupted female descent that ran from mother to daughter to grandaughter, etc., throughout the generations. But this must be quite rare. The Brisker Rav concludes that it must be that a Jew married a woman whom he thought was a non-Jewess, but in reality she was Jewish even though her husband was unaware of this.

This is the meaning of the verse, "I will take from them Kohanim and Leviyim." This refers to Kohanim or Leviyim who thought they were marrying non-Jewesses, but in truth their wives were all Jewish and therefore their descendants are all Kohanim or Leviyim.

We see from this that when Mashi'ach comes, there will be a lot of people who will be discovered to be Jewish.

3) I read recently about an incredible case concerning the "children of the Holocaust" in Poland. Many Holocaust survivors were hidden away with non-Jewish families and never revealed that they were Jewish for fear that this would put their lives in danger. However, Baruch Hash-m, now the situation is easier than it used to be and it is possible to walk in the street in Poland wearing a Kipah.

An elderly woman, who never admitted she was Jewish, decided a few weeks before she died to reveal this to her daughter. However, she told her daughter even more than this: that when her daughter met her husband many years ago, the mother was careful to make enquiries what family the future husband came from, and it was only when she established that he was also from a Jewish "children of the Holocaust" family that she agreed to the marriage! So both the daughter and son-in-law suddenly discovered for the fist time that they are both Jewish!

4) In addition, there are reports of groups of people in different parts of the world who possess certain Jewish practices, which suggests that they may be descendants of various groups of Jews who assimilated (such as Marranos, etc.). There are also the Lemba in southern Africa, the Bnei Menashe in India, etc., who do things similar to Jews. In short, when Mashi'ach comes, we may be in for a lot of surprises!

Kol Tuv,

Dovid Bloom