What one should love, one must know. This also applies to religion. The level of knowledge about religious truths is rapidly declining. Even committed Christians often have only a sparse understanding of the contents of their faith. There is frequently a lack of even the most basic knowledge about liturgical matters. Why is the Holy Mass celebrated the way we know it from our participation and not differently? How has this form of celebration developed? How did its symbolic language come into being? How did the spaces, instruments, and vestments needed for the liturgical celebration come to be, and what role do these external objects play in the celebration of the Eucharist? What names does the Mass have, and what do they mean? It also concerns high theology, the theology of worship in general, and that of the Mass in particular. Finally, the celebration of the Holy Mass itself is presented according to its ritual sequence.