Can a Jew lose their Jewish Status?

Question

Can a Jew lose their status as being a Jew by performing any action (example: performing idolatry, disavowing core beliefs, converting to another religion, etc)? Or once a person is a Jew then they keep this status no matter what?

And if a person would always maintain their status as a Jew (in terms of other Jews viewing that person to still be obligated to follow the commandments), then what in practice would be the significance of a Jew converting to another religion?

Answer 1

For a person who has renounced their Judaism, it appears that while the person doesn't need to undergo a full conversion (on a Torah level), they do need to reaccept the Torah on some level and immerse in a mikvah before returning to the previous status. This seems to be especially true if the Jew literally worshiped idolatry.

1. Rambam, Hil. Mamrim 3:1-3: A person who doesn't believe in the Oral Torah, of his own will (ie: he was not mislead by someone) is no longer part of Israel - "כל אלו אינן בכלל ישראלd"
2. Rambam, Hil. Avodah Zarah 2:5: A Jew who worships idolatry is like a non-Jew in all respects - ישראל שעבד עבודה זרה--הרי הוא כגוי לכל דבר
3. Shulchan Aruch Yoreh Deiah 268:12, Rema: A Jewish apostate who performs Teshuvah (repents) does not need to immerse in a mikvah (in order to return to his former status, on a Torah level); on a rabbinic level he has to immerse and accept upon himself the mizvot ("דברי חברות") in front of three people.

If the person converted to another religion, there may also be procedural differences depending on what religion the person converted to (since some religions may have the status of being idolatrous, and some may not), or what they specifically did to disown their Judaism (or what beliefs they held that were against Jewish core beliefs).

Of course, this is a complicated topic with additional responsa literature, so please see a proper rabbinic authority if this is a practical issue for you.

Further reading:

• Rav Aharon Lichtenstein, Leaves of Faith: The World of Jewish Learning. Chapter 3: Brother Daniel and the Jewish Fraternity, pages 57-84.
• Wikipedia: Who is a Jew?
• Yahoo Answers: What does Halacha say about Jews who have converted to Christianity

Answer 2

Certain sins will cause a Jew to lose his status for many things, but not for marriage, divorce and children. I.e, a Jewish woman's children are always Jewish no matter what sins she's done, and they do not require conversion. However, if a person or group becomes completely disconnected from Judaism for many generations, they will completely lose their Jewish status for everything.

Answer 3

For some related sources, see the subject of Anusim on Wikipedia, specifically, and especially, the short section on Rabbinic Legal Opinions, here: http://en.wikipedia.org/wiki/Anusim#Rabbinic_legal_opinions

"Hakham Se‘adyá ben Maimón ibn Danan, one of the most respected Sephardic Sages after the Expulsion, in the 15th century stated:

Indeed, when it comes to lineage, all the people of Israel are brethren. We are all the sons of one father, the rebels (reshaim) and criminals, the heretics (meshumadim) and forced ones (anusim), and the proselytes (gerim) who are attached to the house of Jacob. All these are Israelites. Even if they left God or denied Him, or violated His Law, the yoke of that Law is still upon their shoulders and will never be removed from them.[4]

Hakham BenSión Uziel, the Chief Sephardic Rabbi of the State of Israel, stated in mid-20th c.

And we still have to clarify on the (subject of) Anusím, to whom the government forbids them to perform Halakhicly valid marriages, if it's necessary to say that their wives must have a Get to permit them (to marry another man), for the reason that, by force of the Law (Hazaqáh), a man does not have intercourse for promiscuity (zenút). . . (In our very case), we deal with those who converted and kept Torah in secrecy and hide their religion because of the gentile surveillance, we say that they do have intercourse for the sake of marriage.

It follows that Hakham Uziel considered anusím as Jews, because only Jews can give or receive a Get, a Jewish divorce.

Rabbi Moshe ben Maimon (Maimonides) stated in the Mishneh Torah Sefer Shofetím, Hilekhót Mumarím 3:3

But their children and grandchildren [of Jewish rebels], who, misguided by their parents . . . and trained in their views, are like children taken captive by the gentiles and raised in their laws and customs (weghidelúhu haGoyím `al dathám), whose status is that of an ’anús [one who abjures Jewish law under duress], who, although he later learns that he is a Jew, meets Jews, observes them practice their laws, is nevertheless to be regarded as an ’anús, since he was reared in the erroneous ways of his parents . . . Therefore efforts should be made to bring them back in repentance (LeFikakh rawí leHah zirán biTeshubáh), to draw them near by friendly relations, so that they may return to the strength-giving source, i.e., the Toráh "

Answer 4

today is hard to a jew loose it's status as a jew since rabenu ovadia says that the generation has the status of tinok shenishbah.

on the other hand there are sins that have the punishment of caret. so his soul wouldn't be jewish after his death.

but even while someone maintain his status as jew he may gain the status of someone that can't be trusted (with food or testimony)