Q: In Rabbi Ginsburgh's book Alef-Beit you mention that the four-headed Shin represents the righteous converts of Israel (page 314.) Do you mean the converts to Judaism? It is my understanding that once a person becomes a convert they are no longer called a convert but a Jew! Is this correct?
A: A Righteous Convert is a full convert to Judaism. He is a one hundred percent Jew, and is called a "citizen" in the Torah. It is forbidden to call a specific convert a Righteous Convert in a derogatory manner or to cause him distress in any way. This is also part of the laws of guarding one's tongue. However, the term Righteous Convert is often used in Jewish Law on a non-personal basis.
The Righteous Convert is the fourth leg or pillar of the Chariot. The Kohanim ("Priests") correspond to Lovingkindness and Abraham. The Levites correspond to Might and Issac. The Israelites correspond to Beauty and Jacob. The Converts correspond to Kingdom and David. Therefore, David descends from Ruth, who was a convert.
The Righteous Convert, called Ger Tzedek in Hebrew, is attached to the concept of Tzedek. Tzedek is the Holy Kingdom. Without the Ger Tzedek, we cannot merit Kingdom.
Bnai Noach, Righteous Gentiles who keep the seven commandments also have great merit, and will receive their portion in the world to come.