In reading Chaim Raphael’s book, A FEAST OF HISTORY: The drama of Passover through the ages, I came across the following description of the Seder ceremony, which I think sums up its role as a common (yet important) Jewish experience:
“The Seder has a unique quality, however, in that it is a ceremony which brings together — and always has throughout history — all kinds of people of Jewish origin, no matter what weight they normally attach to this in terms of belief, practice, political philosophy, social interests or family loyalties. Among our profusion of skeptical Jews … there are not many who will refuse to attend the Seder ‘on principle’ — as they might other Jewish observances. On the surface, nothing is committed by attendance.”
— Chaim Raphael
(Excerpted from: A FEAST OF HISTORY: The drama of Passover through the ages (with a new translation of the Haggadah for use at the Seder). Steimatzky’s Agency, Ltd. together with Weidenfeld Nicolson, London, 1972, pages 17-18.)