Passover - "The Festival of Spring"
The Exodus from Egypt took place in the springtime (the 15th of Nisan), as the Torah states (Ex. 13:4), "Today you are going out, in the month of spring." At that time of year the forces of nature are most manifest and the natural world is at its peak of beauty. To the Egyptians, who worshipped nature, it seemed as if their deity was ascendant. G-d took the Jewish people out of Egypt in the spring to demonstrate that nature has no power or existence of its own and is completely subservient to G-d.
The Sequence of History
One of the reasons it is called seder, literally order or arrangement, is that it alludes to the order or sequence of all of Jewish history in macrocosm. Everything that has ever befallen the Jewish people is part of G-d's plan and is guided by Divine Providence.
(The Maharal of Prague)
Matsa Makes Holy
When a Jew eats matza and introduces it into his body, it sanctifies all his limbs and makes them holy. It is therefore appropriate that we prepare ourselves before performing this great mitzva and ensure that our mouths and bodies are worthy , as it states, "You shall eat matzot in a holy place."
Making it Count
You shall count for yourselves, from the morrow of the Shabbat, from the day on which you bring the raised omer - seven complete weeks shall there be. Until the morrow of the seventh week, you shall count fifty days -- Leviticus 23:15-16
One of the Chassidic masters explained the significance of Sefirat HaOmer - the daily counting of the days and weeks from Passover to Shavuot commanded by the Torah - with the following parable:
A person finds a chest full of gold coins, takes it home, and then proceeds to count them. His counting has no effect on the actual number of coins in his possession: he now has no more and no less than he had before he counted them. But counting them makes them real to him; he can now digest the significance of his find and deliberate how to make use of it.
On the first day of Passover, we were granted the entire "treasure chest." The moment of the Exodus - the moment of our birth as a people - encapsulated within it our entire history. Then, on the following day, began the count: the process of examining our gifts, quantifying and itemizing them, translating them into the resources of our daily lives.