This evening I will lead a Passover Seder observance in my Christian community. We've done it for years and always find it inspiring to reflect on God's liberation from slavery. And it's the occasion for a delicious potluck feast.
This week I saw an article written last spring on Jews' concerns  over Christians celebrating Passover. It seems that more Christian churches are using "Christianized" versions of the seder, reinterpreting the meal's symbols to reflect Christian beliefs. Said one rabbi, "They take our symbols, our holiday, our ritual and start investing them in Christian meaning."
This is a concern that I share. Infusing the traditional text with Christian meaning is both dishonest and disrespectful. For our observance, when I wrote the Haggadah (the text that is the order of the Seder) several years ago, it struck me that the way to deal with the concern was to faithfully follow the traditional Jewish seder. I began with one used by a group of Jewish friends I celebrated with, doing some editing for length without changing the substance. There is then a clear mark of delineation before we celebrate the Eucharist. After the closing prayers of the seder, I say:
"Our Passover Seder of remembering our liberation from slavery has now ended."