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” . (Christ is passing by, 87)
 Cf St Thomas, S. Th. III, q.65, a.3
 Catechesis, 22,3
 John 17:23
 In Ioannis Evangelium tractatus, 26,13 (PL 35,1613)