The word Passover is a translation of the Hebrew word «Pesach.» Hashem PASSED OVER our homes and punished the Egyptians with the plague of the death of the firstborn. Hashem punished the Egyptians for enslaving us, for committing mass murder against us, for torturing us, and for everything else they had done to us.
Hashem did not punish us for our one sin committed while we were in Egypt: many of us had worshiped idols. Hashem passed over us and spared us because we had repudiated the idols and repented from our sin. In fact, we were, at the time of the Plague of the Firstborn, performing the quintessential rejection of our former idol: we were eating it!
The Egyptians worshiped many things: primary among them were certain animals. The Torah tells us in several places that the Egyptians found disgusting the fact that we raised sheep and goats for food. This was because the Egyptians worshiped sheep and goats. Our act of eating the sheep for the Passover Sacrifice, and especially the fact that we made it public by displaying the sheep and goats both before and after eating them, was, to say the least, a slap in the face of our former masters, who had not only enslaved and tortured us, but had also attempted to make us assimilate. Now they were completely helpless to even protest, both when we tied the sheep and goats to our bedposts four days before Passover, and when we hung in the streets and market places the complete skeletons of the animals after we had finished eating them.
And by offering this sacrifice on the 14th day the month of Nissan, and eating part of it that night, we demonstrated our new-found whole-hearted commitment to Hashem.
And the next day Hashem took us out of Egypt. Hashem also displayed our exodus publicly. It took place during the daytime, when all could see. Not only did the Egyptians all see it, so did the many people from other nations whom the Egyptians had enslaved.
Our ancestors came to Egypt as friends and good neighbors. First Joseph the son of Jacob came. He came as a kidnaped slave, was not long afterwards falsely accused and put in prison, and because of the wisdom that Hashem granted him he eventually rose to the second highest post in Egypt, the viceroy to the Pharaoh himself! (Which goes to show that Hashem always knows what He is doing, even if we find it impossible to understand why we suffer so much.)
Joseph helped Egypt through the worst of its times. He predicted a terrible famine, and he showed them how to get through the hard times. Eventually, Joseph’s entire family came down to Egypt, and brought with them tremendous prosperity.
They settled in the nearby land of Goshen, and did nothing to offend the Egyptians. They tended their sheep and goats far away from the Egyptians, and they did not encroach on any Egyptian land. Nevertheless, the Egyptians began to mistreat them.
The Egyptians were afraid that at some point the Children of Israel would rise up to wage war against them, so they enslaved us. Their mistreatment of us knew no bounds.
Hashem gave Pharoah many warnings, but he refused to let us go. So Hashem proved to the universe that He was in control. Indeed, at the time, many Gentiles acknowledged the truth, and some even joined the Children of Israel when we left Egypt.
Hashem proved His power through many public miracles. He also proved thereby that He had chosen us to be those who must fulfill His Commandments and live His Torah.
Fifty-one days later we stood at Mount Sinai and joyfully accepted that responsibility.
Therefore the story and meaning of Pesach (Passover) is our relationship with Hashem. Hashem is our G-d, our personal Savior from all troubles and from sin, our Father, our Guide, our King, our Teacher, our Shepherd, our Rock, and much more besides. And we are His people, His chosen, His followers, His subjects, and much more besides. And the love flows both ways.
Every single act that we are Commanded to do for and during Pesach is a demonstration of that relationship, and highlights a pivotal event or aspect of Pesach. It is all deep with meaning, and therefore it is important for us to study what it all means, and how to do it as Hashem has asked of us.