Becoming a Rabbi requires demonstrating excellence in the knowledge of Jewish Law and customs, in addition to possessing refined character traits.
To become a Rabbi entails taking exams in various aspects of Jewish Law (and passing!), and living in accordance with them.
The Torah, in Numbers 27:8, relates that God told Moses to confer on Joshua the role of leadership for the next generation. God told Moshe to place one hand on Joshua's head. However, Moshe placed both his hands on Joshua's head as a sign that he was transferring the leadership with a full heart.
The Hebrew word for officially becoming a Rabbi is “Smicha”, ordination. The source for using this word — “Smicha” is that it is the same word that the Torah uses for placing the hands of the Rabbi onto the student, Moses and Joshua, in conferring the new “degree” of Torah leadership, that we call “Rabbi”.
This “Smicha” ordination was conferred during Talmudic times in Israel, and in order for a person to receive the title “Rabbi” and be part of the Sanherdrin Court, a short ceremony was held where the Smicha was bestowed.
Today, when a Rabbi receives his ordination from a renowned Rabbi or Rabbinical organization he receives a diploma to prove that he has studied the required Torah texts and passed exams on them. There is no specific time period that is set for this Torah study; each person may and should learn at his own speed. Then, after passing these exams with proficiency and displaying moral fortitude, the Rabbinical candidate receives ordination and receives the title “Rabbi”. This ordination allows a person to become the Rabbi of a synagogue or for a community.
The role of the Rabbi is to serve as the spiritual guide, leader and teacher of the community. He is an accepted authority who may and should answer all questions in matters of a religious nature. He should also be a capable authority to officiate at all of the various types Jewish ceremonies. A Rabbi’s role often involves being involved in personal matters, not only to offer legal rulings, but also to offer Torah-based advice, along with helping people deal with various issues with the assistance of the community, if necessary.
It is important to note that nowadays the title of “Rabbi” is used to denote anyone who is a Torah scholar or a teacher of Torah, without the formal process of passing specific and formal examinations. Rather, many people, especially in Israel, are called “Rabbi” by the members of the community, who recognize them as exemplary Torah scholars and moral role models.