§1. Liturgical actions are not private actions but celebrations of the Church itself which is the sacrament of unity, that is, a holy people gathered and ordered under the bishops. Liturgical actions therefore belong to the whole body of the Church and manifest and affect it; they touch its individual members in different ways, however, according to the diversity of orders, functions, and actual participation.
§2. Inasmuch as liturgical actions by their nature entail a common celebration, they are to be celebrated with the presence and active participation of the Christian faithful where possible.
Source: Code of Canon Law (Vatican.va)