Reprinted with permission from the Second Jewish Catalog, published by the Jewish Publication Society.
Being bar/bat mitzvah and becoming a bar/bat mitzvah (one who is obligated to perform the commandments) do not have a cause-and-effect relationship. In other words, one is a full-fledged member of the Jewish community, able to participate in all aspects of its religious expression and existence, even if one has never had a bar/bat mitzvah celebration. All that is necessary is that one be 12 years old if a female and 13 if a male.
It is common to hear people lament the fact that they did not have the opportunity to celebrate a bar/bat mitzvah. Adult bar/bat mitzvahs have become increasingly common in recent years. Many an individual who did not have the opportunity to have one at the proper age has chosen to observe this rite of passage at a later date. While these ceremonies are quite moving experiences and the efforts to study and prepare for them should be lauded and encouraged, it is important that one remember that the essence of bar/bat mitzvah is the age of the individual. The obligations and responsibilities become theirs whether there is a formal celebration or not.
The ceremony, which is of fairly recent origin, does not make one a bar/bat mitzvah; it merely marks the time when one becomes a “son/daughter of the commandments.” The real meaning of the phrase is not “son or daughter of the commandments” but “one of the commandments” [in the sense of “one who is responsible for performing the commandments”].