The redemption from Egypt was merely a step on the way to true redemption. To understand what we needed to be redeemed from, however, we must go back to the beginning of Creation.
Adam Harishon was put in an almost perfect world; almost, because one thing was left for him to do: to see Hashem in absolutely everything. Having failed this almost superhuman calling, Hashem gave him a different way of accomplishing the same thing and promptly put him to work. By exerting himself to no avail he would eventually come to the conclusion that success is really beyond his control. Toil, Amal, is the prime function of Amalek, the eternal enemy of Divinity. Their goal is to tire Humanity with their efforts; their hallmark being the separation of holiness from the world, making Man's efforts supreme. Although Yehoshua fought them, he was not allowed to conquer them completely because they serve a necessary function as an eternal reminder of the futility of earthly endeavors. The complete refutation to their philosophy, however, was the Mann, the holy bread that came down from the sky. Like rain that comes down plentifully, watering the earth gently and bringing out its fruit, so the Mann came down without effort, always sufficient, perfectly nourishing. Like water, it had no waste; like water, it had the Gemmatria of 90. No wonder G-d commanded that a jar of Mann be kept as an eternal reminder that He was the One who sustained us in the desert for forty years; and despite our efforts it is He who continues to sustain us.
The Egyptians also refuted Divinity. They watered their fields manually, independently, without needing heavenly grace. Their restriction of Heavenly intervention expressed itself in the heart of their name, the middle letters Tzadik Resh that spell Tzar, constriction. These letters split the remaining letters of their name that spell the word Mayim, water, thus preparing their own downfall in the sea.
Separating Heavenly bounty can have other dire results, as the Nation saw when they asked Hashem if He was providing them from the Name Yud Heh Vav Heh or from the Name Ayin, the Divinity that is beyond our comprehension. By implying that they are not one and the same, they were acknowledging Amalek's Philosophy of Separation and were open to their censure. Only when Moshe lifted both his hands together, with Aharon (right) and Hur (left), did the people come to a full realization that only when all Forces are seen as One are we redeemed from the prolonged fight against Amalek.
Adapted from Rabbi Vali's book on Shemos. Questions and subscriptions can be mailed to: the Yeshiva