Purpose.

Many people think that a Bar Mitzvah is a ceremony, however, that isn't what it actually is. A Bar Mitzvah is actually when a Jewish boy turns 13 years old and he becomes a bar mitzvah (son of the commandments) whether or not there is a ceremony to celebrate this event in his life. When a boy becomes a bar mitzvah, according to halacha (Jewish law), he is now considered old enough to take on the religious responsibilities of a Jewish adult.