"Three signs are there for this nation: they are rachmanim, merciful; bayshanim, have a sense of shame; and gomlei chasadim, perform acts of kindness" (Yevamot 89a). The distinguishing mark of the Jewish people is not our observance of Shabbat, kashrut, and a host of other mitzvoth. Important as they may be, they are reflections of the values that are (or at least should be) the true hallmark of the Jew: mercy, shame, and kindness.
Judaism eschews extremism. This obligation to be moderate is codified into law by no less an authority than the Rambam; it is, as he points out, "the path of G-d" (Deot 2:7). Furthermore, the goal is not limited to the development of traits of moderation in our attitude towards money, food, or honour; it is to make them second nature to us.