A mitzvah is a commandment from God. Since Judaism is more of an action-based than faith-based religion, performing mitzvot, or God's commandments, is central to leading a Jewish life.
Judaism believes that all moral laws are derived from these divine commandments. And today the term mitzvah is often used to refer to any good deed.
Kinds of Mitzvot
Jewish tradition holds that the Torah contains 613 mitzvot - 248 positive commandments (mitzvot aseh or commands to perform certain actions) and 365 negative commandments (mitzvot lo ta'aseh or commands to abstain from certain actions). An example of a positive mitzvah is to give charity. An example of a negative mitzvah is not to steal.
Some mitzvot are ethical, and others are ritual. Ethical mitzvot guide our interaction with others, and ritual mitzvot guide our interaction with God. An example of an ethical mitzvah is not taking revenge. An example of a ritual mitzvah is building a sukkah.
Furthermore, the 613 mitzvot in the Bible are called mitzvot d'oraita or commandments of the law. In addition, there are seven rabbinical mitzvot. These are called mitzvot d'rabbanan or commandments from the rabbis. An example of a commandment from the Bible is to keep the Sabbath day holy. An example of a commandment from the rabbis is to light Shabbat candles.
According to Jewish law, Jewish children become obligated to follow God's commandments when they reach maturity. A boy becomes a bar mitzvah (son of the commandment) at age 13. A girl becomes a bat mitzvah (daughter of the commandment) at age 12 in orthodox Judaism and age 13 in more liberal branches of Judaism. After one becomes a bar or bat mitzvah, God's commandments apply to them and they are considered responsible for their actions.
How To Do a Mitzvah
Jewish Law, called Halakha, deals with the application of God's commandments.