Emunah and Bitachon

One of the centrally discussed topics of the upcoming holiday of Shavuos and Jewish life in general is the seeming paradox between having complete Emunah and Bitachon in Hashem Yisborach while fulfilling the mandate of Hishtadlus otherwise known as manly effort that is required by us in the world that we live in. In Parshas Bechukosai the Ramban discusses this and says that the way in which the Brachos are indicated implies that if we obey G-d's word and trust in G-d then G-d will feed us and prvide all of our needs i.e. sustenance, safety...

The reason that we don't experience such a fulfillment of divine intervention is due to the fact that we are unable to have absolute full Emunah and Bitachon in this un-G-dly world. We involve ourselves in earthly instead of heavenly matters and this causes us to have a serious lack of faith in G-d. The question I would like to suggest is why on the holiday of Shavuos, a holiday in which we were told by Hashem himself that he is our G-d, a holiday where every Jew who experienced that event would presumably have the greatest Emunah in the world, is a holiday so centralized around man/woman. Shavuos, in the Jewish calendar falls on the 6th day of Sivan, not the day that we received the entire Torah, but the day in which Moshe Rabbeinu went up to Har Sinai to receive the Torah from G-d. Rav Motti Elon writes that Shavuos is different from other holidays because we celebrate the effort that was put forth from Moshe Rabbeinu, the effort that the entire Jewish people showed, the dedication that Rus, the mother of the Jewish dynasty showed. Even though ideally we should have Bitachon that G-d will fulfill all our needs, we don't live on this level, we live in a world where we need to put forth the strongest of efforts to get close to Hakadosh Boruch Hu, and Shavuos is the holiday where we celebrate G-d's gift to us, and our dedication to G-d.
Have a wonderful Shavuos.