In an article for Yitro 5774, Rabbi Cherki explains that the main revelation of the Exodus was that G-d can be seen both as a heroic warrior and as a teacher.
Moses introduced himself to the Children of Israel as G-d's messenger, sent to fulfill the promise to the Patriarchs – to bring the nation to the Land of Israel and to take possession of it. After Moses kept the first part of the promise by striking out against Egypt and splitting the Red Sea, the people of Israel had faith in him: "And they believed in G-d and in His servant Moses" [Exodus 14:31]. It was clear at that point that Moses was indeed the one hinted at in the verse, "G-d will surely remember you" [Genesis 50:25]. This implies that they saw their stop at Mount Sinai as a station on the way to the Land of Israel and not as a way of preparing to receive the Torah, about which they had no previous tradition from their ancestors.
The promise, "When you take the nation out of Egypt you will worship G-d on this mountain" [Genesis 3:12], was given to Moses alone, while the promise to the nation was, "And I will bring you to the Land" [6:8]. However, when the nation reached the foot of Mount Sinai, they heard a new declaration, "Tell the House of Jacob the following... you will be for me a kingdom of priests and a holy nation" [19:6] – the nation of Israel was given a universal-religious mission. This was an unexpected novel element, and the people therefore needed to decide if Moses should be trusted with respect to this new mission, which was not included in the "original plan." It is therefore not surprising that the nation reacted with skepticism and said, "We will do whatever G-d has told us" [19:8]. That is, their mission included what was promised to their ancestors and not what Moses told them then. And Rashi notes, "Hearing something from a messenger is not the same as hearing it from the King Himself. We want to see our King." (See the same idea in the Rambam, Hilchot Yessodei Torah 8:1 and in the Kuzari, 1:49). In order to remove any doubt from the hearts of the people, a direct public revelation was necessary: "Behold, I come to you in the thickness of the cloud, so that the nation will hear Me speak to you and they will believe in you too forever" [19:9]. If not for this demand by the people, the Torah could have been handed down without a public revelation of the Shechina, the Divine presence, in front of them.
The gist of the revelation was, "I am your G-d, who took you out of the Land of Egypt, from a house of slavery" [20:2]. At first glance, there does not seem to be any connection between this verse and verifying the mission of Moses as the one who gives the Torah. Therefore, Rashi adds, "Since He was revealed at the sea as a 'warrior hero'" (that is, as G-d with nationalistic objectives), "and now as an elder filled with mercy" (as a teacher of Torah, the head of a yeshiva) – "do not say that there are many different gods" (that the nationalistic mission on which I sent Moses is different from the giving of the Torah). "Rather, I am the same One who was revealed in Egypt and at the Red Sea."
We can conclude that that the main purpose of the momentous events at Sinai was to clarify the internal link between the Torah and taking possession of the Land of Israel. Moses, the political redeemer, is the same person as the one who gives the Torah. The politics of Israel and the Torah of Israel are one and the same, as is written, "I am your G-d."
Source: "AS SHABBAT APPROACHES" – a biweekly column in Shabbat B'Shabbato, Yitro 5774, Volume 1508. (Zomet Institute) See: www.zomet.org.il/eng