There is a dispute in the Gemara over which day the Jews received the Torah from Hashem in Sinai, whether on the 6th day or the 7th of Sivan. All agree that the Torah was given on Shabbos. In the inner dimension of Torah, there are two main ways we serve Hashem: starting from our initiative, or responding to Hashem’s influence on us (from below to above or vice-versa). Receiving the Torah was a spectacular, awesome, stupendous, tantalizing, heart-pounding, indescribable influence from Hashem on us. We responded, “we will do then we will understand”! After all the glitz and glamour, we have to “put our money where our mouth is”, to put on Tefillin, give tzedaka, etc. all the mitzvas. This is the bottom line, what the whole show of Matan Torah was all about. Not to go up to the heavens, rather to bring the heavens down here, make this physical world the abode for G-d Almighty himself by fulfilling his commands and desires. According to Rabbi Yossi in the Gemara, on the 7th day is when we received the Torah because that is when we actually started the service of Hashem which is from below to above, pushing ourselves and toiling ourselves to please Hashem and do his will. As it says in the Torah, “return to your tents…” According to the Rabbis in the Gemara (the other opinion), just the fact that Moshe went up to heaven and brought the Torah down here, already showed this level of service. (Likkutei Sichos) This Shavuos we received the Torah all over again, as if for the first time ever. As we say the blessing before studying Torah, “…Blessed are you H’, who gives us the Torah”. Every time we learn Torah, we have to do so like we are receiving it from Hashem on Sinai. Now that we just experienced Shavuot, how much more so do we need to “be there right now”. We even get special help, because Hashem confuses the Satan and he’s out of the picture just like on Rosh Hashana. By staying up all night and studying Torah on the first night of Shavuot, we show Hashem our love, awe, and respect we have for the Torah and him. The Torah says, if you leave me for one day I will leave you for two days (G-d forbid). And we know that “mida tova meruba me midat puranut” (a good merit is rewarded multiple), so the Torah will be with us the entire year and through this we will merit to reveal the master of the world, Alufo shel olam, with the complete and ultimate redemption of the entire Jewish people and all the worlds NOW!