In The Soul of the Apostolate, Dom Jean-Baptiste Chautard, O.C.S.O. (a Cistercian like our own beloved St. Bernard), tells us the true and beautiful inner meaning of Catholic liturgy in these memorable words:
O my soul, you must go into the very heart of the Adorable Trinity and contemplate there the eternal Liturgy in which the three Persons chant, one to another, their divine Life and infinite Sanctity, in their ineffable hymn of the generation of the Word and the procession of the Holy Spirit. Sicut erat in principio...
God desires to be praised outside of Himself. He created the angels, and heaven resounded with their joyous cries of Sanctus, Sanctus, Sanctus. He created the whole world and it magnifies His power: "The heavens announce the glory of God."
Adam comes to life and begins to sing, in the name of creation, a hymn of praise in echo of the everlasting Liturgy. Adam, Noah, Melchisedech, Abraham, Moses, the people of God, David, and all the saints of the Old Law vied in chanting it. The Jewish Pasch, their sacrifices and holocausts, the solemn worship of Jehovah in His Temple, gave this praise, especially since the fall. "Praise is not seemly in the mouth of a sinner."
You, Jesus, You alone are the perfect hymn of praise, because You are the true glory of the Father. No one can worthily glorify Your Father, except through You. Per ipsum, et cum Ipso et in Ipso est tibi Deo Patri...omnis honor et Gloria.
You are the link between the Liturgy of earth and the Liturgy of heaven, in which You give Your elect a more direct participation. Your Incarnation came and united, in a living and substantial union, mankind and all creation, with the Liturgy of God Himself. Thus it is God Who praises God, in our Liturgy. And this is full and perfect praise, which finds its apogee in the sacrifice of Calvary.
Divine Savior, before You left the earth, You instituted the Sacrifice of the New Law, in order to renew Your immolation. You also instituted Your Sacraments, in order to communicate Your life to souls.
But You left Your Church the care of surrounding this Sacrifice and these Sacraments with symbols, ceremonies, exhortations, prayers, etc., in order that she might thus pay greater honor to the Majesty of the Redemption, and make it more understandable to her children, and help them to gain more profit from it while exciting in their souls a respect full of awe.
You also gave Your Church the mission of continuing until the end of time the prayer and praise which Your Heart never ceased to send up to Your Father during Your mortal life and which It still goes on offering to Him, in the Tabernacle and in the splendor of Your glory in heaven.
The Church, who loves You as a Spouse, and who is full of a Mother's love for us, which comes to her from Your own Heart, has carried out this twofold task. That is how those wonderful collections were formed, which include all the riches of the Liturgy.
Ever since, the Church has been uniting her praises to those which the angels and her own elect children have been giving to God in heaven. In this way, she already begins to do, here below, what is destined to occupy her for all eternity.
United to the praises of the man-God, this praise, the prayer of the Church, becomes divine and the Liturgy of the earth becomes one with that of the celestial hierarchies in the Court of Christ, echoing that everlasting praise which springs forth from the furnace of infinite love which is the Most Holy Trinity.