Shabbat is endowed with an amazing capacity. It allows Jews to ascend to a level that is akin to the World to Come, transcend the barriers and masks that this world places between man and his Source of life, absorb the light of faith and Torah, and fully connect with all the mitzvot in the Torah.
The Sages state:
We find attestation that Shabbat is the equivalent of all the mitzvot in the Torah in the Torah, Nevi’im (Prophets), and Ketuvim (the Writings). In the Torah, as it states: “The Lord said to Moshe, ‘How long will you refuse to obey My commandments and My teachings? Note that the Lord has given you Shabbat…’” (Shemot 16:28-29). (y. Nedarim 3:9)
This was after they desecrated Shabbat by attempting to gather manna. We thus see that desecrating Shabbat is akin to violating the entire Torah and all the mitzvot.
The Yerushalmi continues:
In the Nevi’im, as it states: “Moreover, I gave them My Shabbatot to serve as a sign between Me and them, that they might know that it is I the Lord Who sanctifies them. But the House of Israel rebelled against Me in the wilderness; they did not follow My laws and they rejected My rules – by the pursuit of which a man shall live – and they grossly desecrated My Shabbatot…. I warned their children in the wilderness…. ‘Follow my laws…and hallow My Shabbatot, that they may be a sign between Me and you, that you may know that I am the Lord your God. But the children rebelled against Me…’” (Yeĥezkel 20:12-22).
In the Ketuvim, as it states: “You came down on Mount Sinai and spoke to them from heaven; You gave them right rules and true teachings, good laws and commandments. You made known to them Your holy Shabbat, and You ordained for them laws, commandments, and the Torah through Moshe, Your servant” (Neĥemia 9:13-14; see also below 22:2, and the rest of Yeĥezkel 20).
The Sages further declare: “Anyone who observes Shabbat properly, even if he worships foreign deities like the generation of Enosh (when paganism first emerged), is forgiven” (Shabbat 118b). By virtue of observing Shabbat properly, one’s faith is reinforced, and intentional sins are treated as unintentional and are forgiven. The Sages also said: “Anyone who observes Shabbat is distanced from sin” (Mekhilta Beshalaĥ).