The Passover meal was instituted by God to remind the Hebrews that they were once slaves who God had delivered out of slavery and into freedom. It was established to humble them and keep them from becoming arrogant and hard hearted.
It is so easy for us to forget the grace and mercy God has gifted us with and as a result become proud and conceited. This is why we to need to be reminded of what we have been set free from.
On a regular basis we should pause and become aware of this question: Where would I be if God hadn’t touched my life? If we ever lose awareness of this, we may end up looking down on other people who haven’t yet been set free from it.