Catechism of the Catholic Church
“Having passed from this world to the Father, Christ gives us in the Eucharist the pledge of glory with him. Participation in the Holy Sacrifice identifies us with his Heart, sustains our strength along the pilgrimage of this life, makes us long for eternal life, and unites us even now to the Church in heaven, the Blessed Virgin Mary, and all the saints.”
Source: Catechism of the Catholic Church #1419