This is the ultimate meaning of the key concept of the conciliar Constitution, participatio actuosa. For the Church, this participation consists in becoming an instrument of Christ the Priest, so as to participate in his Trinitarian mission. The Church participates actively in the liturgical work of Christ insofar as she is his instrument. In this sense, language about the “celebrating community” can carry a degree of ambiguity requiring true caution (cf. the Instruction Redemptoris sacramentum, §42). Participatio actuosa must not be understood, therefore, as the need to do something. On this point the teaching of the Council has often been distorted. It is a question, rather, of allowing Christ to take hold of us and to associate us with his sacrifice.

Liturgical participatio must therefore be understood as a grace from Christ who “always associates the Church with himself” (Sacrosanctum Concilium, 7). It is he who takes the initiative, who has primacy. The Church “calls to her Lord, and through Him offers worship to the Eternal Father” (§7).

The priest must thus become this instrument that allows Christ to shine through. As our Holy Father Pope Francis recently recalled, the celebrant is not the host of a show, he must not seek the affirmation of the assembly, standing before them as if they were called to enter into dialogue primarily with him. To enter into the spirit of the Council means—on the contrary—to efface oneself, to renounce the spotlight.

Contrary to what has sometimes been maintained, it is in full conformity with the conciliar Constitution— indeed, it is entirely fitting—for everyone, priest and congregation, to turn together to the East during the penitential rite, the singing of the Gloria, the orations, and the Eucharistic prayer, in order to express the desire to participate in the work of worship and redemption accomplished by Christ. This practice could well be established in cathedrals, where liturgical life must be exemplary (cf. §41).