The seventh day is a sabbath unto Hashem thy God, in it thou shalt not do any manner of work, thou, nor thy son, nor thy daughter, nor thy man-servant, nor thy maid-servant, nor thy cattle, nor thy stranger that is within thy gates. EXODUS 20:9 (The Israel Bible™)
We learn in the very first chapter of the Hebrew Bible that after six days spent creating the world and all the beings that live within it, God took the seventh day as a day of rest. Many of the commandments we fulfill are a way of showing God we strive to emulate our Creator and Shabbat is no different. Just as God rested on the seventh day, so too do Jews all over the world refrain for 25 hours from any form of work. In this way, we can show our Beloved Hashem how deeply we cherish Him and His commandments. To welcome in the Sabbath, we are instructed to light the flames and make a special blessing on a cup filled with wine. Doing thus initiaties the serious, spiritual and uplifting day that is Shabbat.