At the end of Genesis and in the book of Exodus, the development of the descendants of Jacob from a family (Genesis) into a nation (Exodus) is documented. I have been asked numerous times is Judaism a religion or a nation?
Most classic religions do not only apply to a particular nation. A religion is a system of belief and a system of action, a system of thought and of ethics without, generally, a nationalistic component.
Judaism is, however, quite different. In Judaism there is a strong national component and you cannot divorce the national component from the spiritual component. They really are bound up together. As we see from the very beginning of the history of the Jewish people they are totally and completely tied together. The people to whom G-d appeared, and gave the Torah, were not chosen at random but were descendants of Abraham, Isaac, and Jacob. They experienced slavery in Egypt, the Exodus from Egypt, the sojourn in the desert, and they come to Mount Sinai and G-d gives this nation the Torah. So the Torah is given to a nation and the nation is designated as the people who are chosen to keep the Torah.
So how do we understand this? Clearly Jewishness is not totally genealogical, because otherwise conversion would not be an option; but we know that in Jewish tradition conversion is possible. One cannot become Japanese, Aryan or German, but one can become Jewish. Why is that so?
So Judaism is not purely genealogical because there is such a thing as conversion. But on the other hand it is not purely ideological, because if one was born to a Jewish mother one is automatically Jewish. I think the solution is found in how anyone becomes Jewish. The souls of the Jewish people, descendants of Abraham, Isaac, and Jacob, stood at Mount Sinai and received the Torah and that is how we became Jewish. So therefore if you are born to a Jewish mother as I was, you automatically have within your soul the experience of revelation at Mt. Sinai.
When a non Jew wants to become Jewish he or she must also go through a Sinai experience. They have to go to a mini-Mount Sinai. Indeed, the Talmud, and later Maimonides, derive all the laws of conversion from what the Jews experienced at Mount Sinai. The convert accepts the Torah unconditionally as the Jews did at Mount Sinai when they said “we will do and we will listen.” The male convert is circumcised just as the Jewish men had been circumcised before Mt. Sinai. The Jews purified themselves before the revelation, so also every convert must purify him or herself in a mikvah before their acceptance of the Torah. The Jews entered into the covenant with G-d in the presence of, and under the supervision, of Moses. The circumcision, immersion and acceptance of commandments by the convert must also be done under the supervision of a Jewish court, a Beis Din, who represent Moses.
Once the convert goes through their quasi-Sinai, as Maimonides points out, they may say in their prayers “My forefathers Abraham, Isaac, and Jacob” and they may say “You commanded our fathers” that “You gave our fathers the Land of Israel.” Because just as every native born Jew is a child of Abraham, Isaac, and Jacob, Sarah, Rivkah, Rachel and Leah, so too is every convert a child of the Patriarchs and Matriarchs. We are children by birth, and the convert is a child by being a student.
So, Judaism is a bit of both – religion and nationhood. We are a nationality, but one that can be joined. We are an ideology, but one which is inherited.
It is interesting to note that Maimonides tells us in the Laws of Repentance that a Jew who does not transgress any sins and keeps all the commandments, but does not mourn and feel the pain when the nation mourns, and does not rejoice when the nation rejoices is considered an apostate, a member of a foreign religion. So even though this Jew is technically not transgressing and is keeping the commandments, since he does not participate in Jewish nationhood and peoplehood, he is adhering to a way of life that is very similar to Judaism, but is not Judaism. Being a good Jew means not only keeping the commandments but being part of the Jewish community; feeling pain when the Jewish people feel pain, rejoicing when the Jewish people rejoice, fasting when the Jews fast.
This is the reason that one of the essential components of the Jews accepting the Torah at Mount Sinai was a unity of the Jewish people. No individual can keep all 613 Commandments, they can only be observed by the Jewish people as a whole.
So the Jewish people, it is not a religion per say, it is a nation. The nation has a land. The nation has an ideology. The nation has self-determination. And the nation has its own identity and its own ethics and morals. And that is really what Judaism is about. That is why, the Kuzari says, it was not given to the Patriarchs and Matriarchs, as great as they were, because they were individuals and were not yet a nation. G-d waited until there was an entire nation, forged in the furnace of Egypt, matured by the Exodus, the slavery and the redemption from Egypt and then elevated at Mt. Sinai by the Divine revelation.