Judaism refers to the entire Jewish religious system—its laws, traditions, festivals, and way of life rooted in the Torah. Paul uses the term in Galatians to describe his former zealous commitment to the ancestral traditions that he once defended with such passion. The word encompasses both the theological framework and the lived practice of Jewish faith in the first century, including its dietary laws, Sabbath observance, temple worship, and the rich body of rabbinic interpretation that distinguished Jewish identity.