In an article for Re'eih 5773, Rabbi Cherki notes that while an individual may lose his rights as a Jew, the nation as a whole remains children of G-d forever.
It is written in this week's Torah portion, "You are sons of your G-d" [Deuteronomy 14:1]. It is a great honor to be the son of the Holy One, Blessed be He, as an entire nation, as is written, "My firstborn son is Israel" [Exodus 4:22]. This expression of honor obligates us to make a special effort. But what happens when we do not act as a son should? The rabbis do not agree about the answer to this question.
Rabbi Yehuda says, when we act as sons we are called sons but if not we are not called sons. But Rabbi Meir says, in any case we are still called sons. (Kidushin 36a). Rabbi Meir has several proofs of his opinion. For example, "Destructive children" [Isaiah 1:4] – we are called children even when we are destructive. "Sons who are not faithful" [Deuteronomy 32:20] – even though they have no faith. Or, "And it will be, instead of it being said to them, 'You are not My nation,' it will be said, 'sons of the living G-d'" [Hosea 2:1]. Many verses can be used to show that Rabbi Meir is correct.
Therefore, even though in general when there is a dispute between Rabbi Meir and Rabbi Yehuda the halacha follows the opinion of Rabbi Yehuda, this time is an exception. In this case we rule according to Rabbi Meir. The Talmud continues to discuss the opinion of Rabbi Meir at length because his opinion is accepted as the halacha. This is also what the Rashba writes in his responsa (194; 242).
The Rashba was asked if the dead body of an apostate Jew causes another person in the same "tent" to become ritually impure. The basis for this question is the known principle that dead bodies from the other nations do not impart ritual impurity in the same way as the body of a Jew. A Jew passes on impurity if his body is in the same "tent" with a living person, while a non-Jew is a source of impurity only if his body comes into physical contact with another person. Thus, the question that was asked was whether an apostate ceased to be a Jew in halachic terms. And the question was made even stronger by noting the fact that one is allowed to charge interest on a loan to an apostate, and that his wine is considered Gentile wine used for a libation and is therefore unfit to drink. The answer of the Rashba was that an apostate imparts ritual impurity in the same way as any Jew. An apostate can be charged interest because the prohibition of interest is derived from a verse which refers to "your brother," and this person does not act as your brother, he has thus abrogated his right to be treated as a brother. But ritual impurity is not related to brotherhood but rather is due to the special love for Israel, who are called "sons" – following the opinion of Rabbi Meir. No matter what, they are called sons.
It is characteristic for Jews to try to escape from their unique traits. However, the very fact that somebody writes a book called "How and When I stopped being a Jew" is testimony of the strong link he feels to Judaism.
We must not think, based on what we have written so far, that Rabbi Yehuda feels that the unique treasure of Judaism can be transferred from one nation to another. There is no way that Rabbi Yehuda can be accused of holding an opinion which was the very basis of Christianity! Rather, he feels that it is possible for an individual to lose his trait as a son. He definitely does not think that this can happen to the entire nation.
Source: "AS SHABBAT APPROACHES" – a biweekly column in Shabbat B'Shabbato, Re'eih 5773, Volume 1485. (Zomet Institute) See: www.zomet.org.il/eng