The article contains the previously unpublished address of the author at the international gathering of Communion and Liberation held at Corvara in August 1989. The text, after slight revision, was republished in the miscellaneous volume Un avvenimento di vita cioè una storia (same title, EDIT-Il Sabato, pp. 394-412) and in L’avvenimento cristiano. Uomo Chiesa Mondo (BUR, 1993, pp. 29-50; last BUR edition, 2003).