"The power of worship is a derivation in the Church from Christ's own priesthood; for, Christ is the Priest. He exteriorly manifested his sacerdotal power—mysterious and invisible in itself—when, instituting the cult of the New Law on the ruins of that of the Old Covenant, he gave to his death on the Cross the character of a definitive sacrificial offering, of a supreme liturgy, in which the beautiful fruits of grace would be poured out upon the world and enter the hearts of the faithful through the channels of Baptism, the Holy Eucharist, and the other sacraments.
There will be all throughout history, therefore, men incorporated in Christ the Priest, participating in the spiritual unction of his sovereign priesthood, drawn in the wake of his divine liturgy. The cultic mediation of the Head is transmitted to and diffused throughout the entire Body. Having been perfected in the Savior, it remains imperfect, or incomplete, in his members. These latter must now work through him, with him, and in him for the salvation of the world. This cultic mediation entered into time in order to remain really and continually present there, not in order to be immediately torn away from it, leaving men with only a memory -even if the most divine of memories! This, then, is the mystery of the primary priesthood of the Head, giving rise to a purely ministerial and secondary priesthood of the members -of the Body, which is the Church. The Church will exist in her fullness only where the priesthood of Christ -through Christian worship- continues to be exercised."
-Charles Cardinal Journet in Theology of the Church.