Catechism of the Catholic Church 1213
The Holy Eucharist completes Christian initiation. Those who have been raised to the dignity of the royal priesthood by Baptism and configured more deeply to Christ by Confirmation participate with the whole community in the Lord's own sacrifice by means of the Eucharist.
At the Last Supper, on the night he was betrayed, our Savior instituted the Eucharistic sacrifice of his Body and Blood. This he did in order to perpetuate the sacrifice of the cross throughout the ages until he should come again, and so to entrust to his beloved Spouse, the Church, a memorial of his death and resurrection: a sacrament of love, a sign of unity, a bond of charity, a Paschal banquet in which Christ is consumed, the mind is filled with grace, and a pledge of future glory is given to us.
Catechism of the Catholic Church 1322 & 1323
Come, Holy Spirit, fill the hearts of your faithful and kindle in them the fire of your love. Send forth your Spirit and they shall be created, and you shall renew the face of the earth. Let us pray. O God, who have taught the hearts of the faithful by the light of the Holy Spirit, grant that in the same Spirit we may be truly wise and ever rejoice in his consolation. Through Christ our Lord. Amen.