Catechism of the Catholic Church
“There is no surer pledge or dearer sign of this great hope in the new heavens and new earth ‘in which righteousness dwells,’ than the Eucharist. Every time this mystery is celebrated, ‘the work of our redemption is carried on’ and we ‘break the one bread that provides the medicine of immortality, the antidote for death, and the food that makes us live for ever in Jesus Christ.'”
Source: Catechism of the Catholic Church #1405