Shabbat, the seventh day of the week, is a reminder that God is the creator of the entire world. Just as He created the world in six days and rested on the seventh, we use our creative powers to work for six days, and rest on the seventh. By keeping the Shabbat, we affirm our belief in Hashem (God) as the Creator who is continuously responsible for everything that happens in the world. The Land of Israel also has a Shabbat of its own, once every seven years. By abandoning the fields during the Sabbatical year and putting our sustenance in the hands of the Lord, we affirm our belief that He is intimately involved in everything that happens in our lives. We owe all of our success to Him, and we believe that He will provide for us, even if we are not working the land.
Source: Israel in the News