In my thinking, I believe that the Passover was considered not only an act of faith and obedience, but also as a sacrifice as well.
Everyone was instructed to eat roasted lamb, unleavened bread, and bitter herbs. The meat was not to be prepared any other way than roasted and it was to include the legs, heart, liver, and head. They were only to eat this meat for one day, not the next. If they had left any over, they were to burn it. They were not to use yeast in the bread, or even have yeast in their households. This would be mentioned many times through chapters twelve and thirteen. The people were to wear their traveling clothes while eating their feast and were to be prepared for the journey. They were to be wearing their walking shoes and were to have their walking sticks with them. .
In verse eleven, god gives a name to the event, saying, "This observance shall be called the Lord's Passover (12:11)." He goes on to explain the reasoning for giving it this name and also explains the events that will transpire following the feast. He says, "For I will pass through the land of Egypt tonight and kill all the oldest sons and firstborn male animals in all the land of Egypt, and execute judgment upon all the gods of Egypt for I am Jehovah.".
This name "Jehovah" appears several more times through out the chapter and in chapter eleven. Earlier in Exodus we are presented with this term and there are implications of its meaning. God is speaking to Moses and He says, " Tell them [the people of Israel], "Jehovah, the God of your ancestors Abraham, Isaac, and Jacob has sent me to you." This is my eternal name to be used through out generations (Exodus 3:15)." He tells Moses and the people that He is the same God that was Abraham, Isaac, and Jacob and He will be with the generations to come. This suggests that He is an unchanging, eternal God and He will always be with His people. I also believe that he chose the names Abraham, Isaac, and Jacob so that they would remember the covenant He made to Him and also knew He is a covenant-keeping God.