The holy Mass brings us face to face with one of the central mysteries of our faith, because it is the gift of the Blessed Trinity to the Church. It is because of this that we can consider the Mass as the centre and the source of a Christian's spiritual life.
It is the aim of all the sacraments. The life of grace, into which we are brought by baptism, and which is increased and strengthened by confirmation, grows to its fullness in the Mass. "When we participate in the Eucharist," writes St Cyril of Jerusalem, "we are made spiritual by the divinizing action of the Holy Spirit, who not only makes us share in Christ's life, as in baptism, but makes us entirely Christ-like, incorporating us into the fullness of Christ Jesus."
This pouring out of the Holy Spirit unites us to Christ and makes us acknowledge that we are children of God. The Paraclete, who is Love, teaches us to saturate our life with the virtue of charity. Thus consummati in unum: "made one with Christ," we can be among men what the Eucharist is for us, in the words of St Augustine: "a sign of unity, a bond of love."
I will not surprise anyone if I say that some Christians have a very poor concept of the holy Mass. For them it is a purely external rite, if not a mere social convention. This is because our poor hearts are capable of treating the greatest gift of God to man as routine. In the Mass, in this Mass that we are now celebrating, the most Holy Trinity intervenes, I repeat, in a very special way. To correspond to such great love, we must give ourselves completely, in body and in soul. We hear God, we talk to him, we see him, we taste him. And when words are not enough, we sing, urging our tongue — Pange, lingua! — to proclaim to all mankind the greatness of the Lord.
www.escrivaworks.org/book/5/87