Before the giving of the Torah there was no strict legal definition of a Jew, because the law had not yet been given. This means that the people who came to Mt. Sinai were not Jews (in a legal sense) yet. In fact, the Revelation at Mt. Sinai can be viewed as a mass conversion to Judaism of millions of descendants of Abraham. In this sense, every Jew is descended from a convert; some go back to Sinai, and some later in history. The idea of conversion after Mt. Sinai is mentioned in the Torah itself and we are exhorted more than thirty times (!) not to oppress a convert. For instance, "And when a convert lives amongst you in your land do not oppress him. The convert shall be like one of your citizens and you shall love him as yourself, for you were strangers in the Land of Egypt..." (Leviticus 19:33-34)
We derive our obligation to welcome a convert from one of the most famous converts in history, Yitro, the father-in-law of Moses. As the Midrash states: "I am the One who drew Yitro near and did not reject him. You also, when a person comes to convert and does this for the sake of Heaven, draw him near and do not reject him."
What does the conversion process involve? It requires that the non-Jew go through a re-enactment of the revelation at Mt. Sinai. As Maimonides writes: "The Israelites entered into the covenant with three things; circumcision, immersion, and sacrifices. Circumcision was performed in Egypt, as it is written 'and all uncircumcised (males) shall not eat of it (the paschal lamb).' Immersion (purification) was performed in the desert before the giving of the Torah, as it is written 'and you shall sanctify yourselves today and tomorrow.' And at this time sacrifices were also brought...So too for all generations, a gentile who wishes to enter into the covenant, to find shelter under the wings of the Shechina (Divine Presence) and to accept upon himself the yoke of Torah, requires circumcision, immersion and acceptance of a sacrifice (at the time of the Temple)."
There are three basic components to the contemporary conversion process: Circumcision (for males), immersion in a mikveh and as Maimonides mentions, the acceptance of the "yoke of Torah." This is just like the Jews at Sinai who unconditionally accepted all the commandments when they said "We will do and we will listen." All the above must be done in the presence of a Beit Din (Jewish court) because they are the representatives of Moses, the lawgiver.
If any one of the above three things is omitted, the conversion is invalid. A convert to Judaism must be prepared to accept all the commandments of the Torah without exception. If there is no acceptance of the commandments, even if three Orthodox Rabbis rule that the person is Jewish, he is not Jewish. Without acceptance of the Torah's commandments, the conversion would just be a sham.
Once a person sincerely converts to Judaism, they are 100% Jewish, and we are obligated to love, welcome and accept them into our people. When they recite the prayers, they refer to the Patriarchs and Matriarchs as "our fathers" and "our mothers." At the Passover Seder they say "God took our fathers out of Egypt." They are full-fledged members of the Community of Israel.
In general, we do not encourage someone to convert. There are two reasons for this:
First of all, we believe that when a gentile keeps the seven Noachide laws, he merits a portion in the World-to- Come, and therefore there is no imperative for him to become Jewish. If, like the Christians and Moslems, we believed that those of other religions are condemned to damnation, then we also would desire to convert people. However, we believe that a person can be completely righteous and merit the World-to-Come without conve
