Naseh Venishmah- In this world we will do and in the next world we will understand. The Lubavitcher Rebbe notes that we put on the teffilon on the arm first and then we put on the Teffilon on the head , the action is the most important thing in this world.
The theme of Shavuot is Emunah which is manifest thru learning Torah.
How are Har Sinai, learning Torah and Faith connected?
What holiday is Shavuos very similar to but is celebrated in a very different way?
Simchat Torah is also a celebration of the Torah but we do not read from the Torah all night we dance with the Torah . Why ? The The Dubno Hamagid gives a Mushel A king had a beautiful daughter but he did not want anyone to marry her just for her beauty so he secluded her and told nobleman they could marry his daughter if they agreed without meeting her first. One man agreed , he was dancing nervously at the wedding and speaking to his bride as much as he could, studying her, then several months later he prepared a much larger banquet in which he danced joyously all night.
Shavuos is the wedding , simchat Torah is after you have gotten to know and understand the person and can be joyous and connected without deep study, using a different channel, utilization of both methods is healthy.
At Har Sinai we displayed our faith and began studying Torah. We recreate this event every year.