It is uncertain whether the Passover was a Seder or not. Does that change the way you think about the Last Supper as a result? Did it have to be a ritual sacrifice or meal in order to be important?
The Seder was changed from a ritual practice to a symbolic practice. How do we understand these symbols? Is it more important to know the ritual origin, or the symbols as we now know them? Are both important?
How have you seen a ritual (or rituals) change over time? Have they changed meaning in a significant way?
Think about a ritual you currently participate in. How would you understand that ritual if there was no longer a location to do it? Could it still be done?
People do not always understand why they perform rituals. Do you need to understand a ritual in order to properly participate?