In the course of a discussion of the Christian liturgy and religious rituals in general, Mircea Eliade maintained that every religious festival, any liturgical time, represents the reactualization of a sacred event that took place in a mythical past, since words and gestures of a ritual are thought to be charged with a power of reactualization so that the event imitated is believed rendered present for the community's welfar. My analysis of the Piacentinian Christmas texts will be based on the phenomenological theories of religion elaborated by Eliade and Odo Casel. It will examine how the medieval Mass was not only a religious ceremony in praise of God but also a cultic experience in terms of the time and space of the ceremony. The liturgical apparatus will be considered as the actual vehicle that creates the proclaimed reality of the celebration, because it is within the power of the Mass to bring us into the same temporal dimension with the saving deeds of Christ and to place us in their immediate presence. By indicating the complexity of dimensions involved in religious practice, its ritual, mythological, doctrinal and experimental aspects, this phenomenological approach to the medieval Christian liturgy implies that the telos of each individual Mass goes beyond the liturgical celebration itself. It would seem to be of some interest, then, to subject to a detailed investigation those texts that were selected in a specific diocese at a certain time to achieve such a telos.