53 Although the private prayers of Christians are to be considered entirely appropriate, it is nevertheless advantageous to recall to their minds the chief and essential purpose of the celebration of the Sacrifice of the Altar, as it is stated in the Canon of the Latin Mass: "in the first place . . . for Thy holy Catholic Church, that it may please Thee to grant her peace, to protect, unite, and govern her throughout the world." These profound intentions of the Church will be more readily grasped by the faithful, if they will meditate on the doctrine laid down by Us in the Encyclical Mediator Dei, in which We taught that every Eucharistic sacrifice must be considered an action performed in the Church's name, because "the celebrant at the Altar takes the part of Christ as our Head offering in the name of all His members."
Source: Fidei Donum (Vatican.va)