The Liturgy is a great subject, sometimes an inflammatory one, known to generate devotion, enthusiasm, even heat. But there is a possibility of avoiding the controversial, making the study exploratory, seeking out the facts and their relations which help us to live better the life of union with God. So, for security reasons, it is well to begin by putting liturgy in its place by defining terms.
Liturgy is the Church's official dispensation of the Mysteries of Christ. It is the ‘whole’ body of the official prayers and sacramental actions whereby the communication of men with God is carried on in the Church'; ‘the life-dispensing, life-preserving, and life-restoring activity of Ecclesia, the Mystical Christ‘. In less technical words: Liturgy is the official communication of divine Life by Christ through the Church. The liturgy consists of four inter-related parts: the sacraments, the sacramentals, Divine Office and ritual prayers, and the Liturgical Year—all centred in and drawing their source from the Holy Sacrifice of the Mass which, as the re-enactment of Calvary, is the core of the liturgy.