In this Parsha - G-d gives us the Torah.
Before the giving of the Torah, the spiritual status of the world could be described by the verse, "The heavens are the heavens of G-d, but the earth He gave to man." The heavens, the spiritual realms, were self-contained, meaning, they had no influence on the material realm. And mankind, living as we do in the earthly realm, had no way of tapping into the spiritual.
At the giving of the Torah, all this changed. G-d allowed for communication between these two realms. As it is written: "And G-d descended on Mt. Sinai." G-d made Himself accessible to mankind. It is also written: "And Moses ascended unto G-d," meaning, we were given the opportunity to elevate ourselves and our surrounding environment and provide it with spiritual content.
Sinai is not a one-time event, or only a story of history but rather the establishment of a channel that continues to enable man and G-d to relate to each other and has relevance to our lives today.
The Torah contains teachings that brings G-d within reach of our understanding. When a person studies a law from the Talmud, he is understanding G-d's essence. And thus the Torah gives us an opportunity to relate to G-d thru our minds. And through performing His Mitzvot, also our deeds can be brought into connection with Him.