A quick recap- the format of Haggadah of Pesach is based on Shema Yisrael Hashem Elokenu Hashem Echad , which is our daily statement of Emunah.
There are allusions to this in the Haggadah:
At the start we say הא לחמא עניא- we invite guests in. Why? Because in order to recognize that Shema Yisroel- that we are a part of Yisrael and not just individuals, we first have to connect with the Jewish people by inviting them to eat with us.
And we end the seder with אחד מי יודע- Who knows One, because our goal is to recognize to that Hashem is the אחד- the One and Only.
That leaves the middle portion, which corresponds to “ה' אלקינו.” Hashem Our G-d. What does that mean?
Ramban says that when we kiss mezuzah we remember Yetziat Mitzrayim. The Brisker Rav questions this; where is Yetziat Mitzrayim in the mezuzah? He answers with another Ramban which asks why the Shema say Hashem “ אלוקינו”
Why our G-d?
He explains that this is Our G-d that took us out of Egypt and made a special pact with us and deals with us in a special way.
He is our G-d.
When Hashem introduces himself at Har Sinai He says, I’m Hashem your G-d that took you out of Mitzrayim - He doesn’t say I am Hashem that created the world - He says your G-d that took you out of Mitzrayim because He’s speaking specifically with us, the Jewish Nation.
Therefore, Ramban says, every day when we say keriat shema- when we get to Hashem Elokenu, this is referring to Our G-d of Yetziat Mitzrayim. It’s built into Keriat Shema. Ramban doesn’t say this next part, but I believe that perhaps we recite the third paragraph of keriat shema in order to explicitly talk about Yetziat Mitzrayim. As it says it says in the gemarah, we have to connect yetziat Mitzrayim with Keriat Shema. Why? Why in Shema? Because reciting the Shema is the catalyst for the proper statement. Shema is our pledge of allegiance twice a day (Shulchan Aruch says ladies must also say this at some point each day).
Shema Yisroel- Hear O Israel
Hashem Elokenu: Our G-d who supervises the Jewish people in a special way.
Hashem Echad- Hashem is the one and only.
These understandings come from the seder.
G-d demonstrates that:
Shema Yisroel- You-the nation of Israel, you are different He took us out
Hashem Elokenu- He’s the boss over us.
Hashem Echad-He’s the only one - there’s no one else to turn to.
This daily pledge comes from Yitziat Mitzrayim.
We start the Haggadah with Shema Yisrael, by inviting guests and being a part of klal Yisrael.
We end with Hashem Echad
But the whole middle is the Meat and potatoes: Hashem is our G-d He took us out of Mitzrayim
The Rosh says, if you believe אנכי ה׳Hashem is your G-d but you don’t believe that
אשר הצאתיך Hashem took you out of Mitzrayim, it’s not a full belief. It has to connect to Yetziat Mitzrayim.
He states: If someone doesn’t believe “I took you out of Egypt” he is not a believer, because this is what separates us from the other nations. Hashem took us out and watched over us with Hashgacha peratit , it’s the foundation of our Torah and our religion.
That’s why the better the Seder is, the better the Keriat Shema will be the entire year.