MAZEL TOV! Today begins the journey towards one stage of a much longer Jewish journey.
Bar and Bat Mitzvah is about ritual maturity; about growing up as a Jew. While it marks the time when a young person becomes a fuller member of the Jewish community, it is also about moral responsibility, connecting to Torah, to community, and to God.
The name “Bar Mitzvah” is a Hebrew-Aramaic term, signifying a person who is obliged to observe the precepts of the Jewish religion. The term first appears in Talmud where a minor and an adult non-Jew living in a Jewish household are both described as not being Bar Mitzvah, since neither are obliged to fulfil the commandments of the Torah. It is only in the last seven hundred years or so that the term "Bar Mitzvah", and more recently "Bat Mitzvah", have come to be used in their present double sense, referring first to the child who becomes a Jewish adult man or woman, and also referring to the ceremony that celebrates this transition.
Before the Middle Ages other words were used to describe a child's coming of age. A boy was described as "Gadol" (big, or adult) and similarly a girl was described as "G'dolah". These terms refer to the child physically reaching the age of puberty. A boy might also be called "Bar Onesh" which means "liable for punishment". Before this time, the parents had to pay the price for their child's misdemeanours. Now the child was considered old enough to be responsible for their own actions. When the child became "Bar Onesh", the father would thankfully bless God for having released him from the burden of being responsible for the youngster's behaviour.
Modern Judaism has come to stress the Bar Mitzvah and Bat Mitzvah ceremonies as celebrations marking the age at which one is considered to be a religious adult member of the community who can responsibly fulfil the commandments. In Orthodox settings the boy can now be part of the Minyan (the quorum of ten adults), lead the prayers and read from the Torah. In most Reform synagogues, as well as in many Conservative and Liberal communities, these responsibilities apply equally to girls who are Bat Mitzvah as well as to boys who are Bar Mitzvah. In these synagogues, it is the general custom to have these ceremonies take place at the age of thirteen both for boys and girls, and all youngsters would have a similar ceremony, and would be expected to participate in the service according to their ability and not according to their gender. It is then their responsibility and privilege to observe the Mitzvot; for example, they have the personal responsibility to fast on Yom Kippur as well as the public privilege of being able to lead services.
It ought to be mentioned that thirteen is not the age at which one becomes a full adult in every sense. The Torah has twenty as being the age at which one is liable for poll tax and for military service. Priests had to be thirty before they were considered mature enough to lead Temple rituals. The Rabbis held a debate as to what was the minimum age at which one could deal in real estate property, and some said it should be eighteen and others said it should be twenty. It is Jewish tradition that a person should be over forty before they are ready to learn about mysticism.
In other words, thirteen is just the beginning of adult Jewish life. Jewish study is as deep and as complicated as any medical or legal training. How many people would trust a lawyer who had a thirteen year olds knowledge of law? How many people would entrust their lives into the care of a doctor who had stopped his medical studies at the age of thirteen? It is against Jewish tradition to stop one's studies at thirteen and think oneself qualified as a Jewish adult.