Nothing, other than the existence of G-d, is more central to Judaism. In fact, the Torah makes clear that observance of Shabbat is the ultimate recognition of G-d's creation of Heaven and Earth. This is no minor matter, since, until the twentieth century, creation was viewed by most people as an untenable concept. The known laws of physics not only denied the possibility of a creation ex nihilo (from nothing), but the very idea of the world not having existed forever, was decried as impossible, from the time of the classical Greeks until the early twentieth century. The idea of the Big Bang took quite a bit if time to be accepted by science. Actually, it was first suggested by RAMBAN in the fourteenth century, but was largely ignored) Even now, it is difficult to explain, and no one knows for sure exactly what happened. Judaism has always maintained a view that the world started at a finite time in history, and was the result of a great master plan; not an accident. That, in the Torah, violation of Shabbat is a capital offence, shows its severity. In Jewish tradition, Shabbat observance has always been the defining feature of a religious Jew. To ignore Shabbat meant to deny creation, and by inference, to deny G-d Himself. We find in the Torah that G-d "rested" on the Shabbat (whatever that means), and so must we. We are also forbidden to make servile use of our beasts of burden, as well as making servile use of our non Jewish employees. Only a true life and death situation permits violation of the Shabbat. Loss of money or property is never a consideration. In the Torah, we are commanded not to do "Melachah". This does NOT mean "work". It means skilled, creative activity. The word is also used in connection with building the tabernacle in the desert, and we have in the Oral Tradition the idea that the same thirty nine types of labor involved in building and maintaining it, are the same labors Biblically forbidden on Shabbat. By Torah law, exertions is not even considered a problem. You may feel free to carry your couch inside your home all day. However, we read in Isaiah (58:13-14) that we are to avoid our weekday pursuits, (even concerning how we speak or where we go), in order to call the Shabbat "oneg" ( a delight). (Please remember that commands found in the post Torah Biblical books are considered as being "rabbinic" rather than Biblical.). Just as blowing the Shofar on Rosh HaShanah is a simple mechanical act, imbued, however, with numerous layers of intent and association, the Shabbat is built upon numerous rules and regulations, designed to inculcate a sense of delight, happiness, transcendence,peace and contentment. These laws can be divided into several categories. The "Biblical" laws; or activities that come under the headings of the thirty nine categories mentioned above, the rabbinic decrees; some of which are meant as "fences" around a Biblical law, while others are designed to be "mood setters", in keeping with the spirituality of the day. The primary difference between the Biblical and rabbinical laws is that the former may not be violated except in the case of possible loss of life. The latter may be ignored in cases of extreme discomfort. There are later local enactments, which have, arguably no halachic meaning, as well as "svarot", theoretical constructs, that impart Biblical meaning to things and actions that have no actual source. These came in mostly in the seventeenth, nineteenth and twentieth centuries. Many of these are controversial. Not for discussion now, but thus we come to the situation where most Ashkenazim consider brushing teeth and using solid soap as Biblical prohibitions. Most Sepharadic rabbis consider this comical, and the results of faulty logic. In this series, I plan to go through a typical Shabbat, pointing out both what we do and what we feel, as well as differences in customs, especially those based on svara. Please bear in mind that the laws of Shabbat are vast, taking up two full tractates in Talmud (Shabbat and Eruvin). It would be impossible to cover everything, but I hope to provide an understandable and workable framework. "The work is not ours to complete, but neither may we neglect it".