Catechism of the Catholic Church
“In an ancient prayer the Church acclaims the mystery of the Eucharist: ‘O sacred banquet in which Christ is received as food, the memory of his Passion is renewed, the soul is filled with grace and a pledge of the life to come is given to us.’ If the Eucharist is the memorial of the Passover of the Lord Jesus, if by our communion at the altar we are filled ‘with every heavenly blessing and grace,’ then the Eucharist is also an anticipation of the heavenly glory.”
Source: Catechism of the Catholic Church #1402