The celebration of the Mass is the most important activity of the Church, “the source and summit of the Christian life” (Catechism 1324). It is an action of Christ and his Church that memorializes the Last Supper at which Jesus shared his body and his blood with his disciples. It is an action that makes present the death and resurrection of Christ, the Paschal Mystery that brought redemption to the entire world. It is an action of Christ and his Church in which Jesus is offered as a sacrifice to his Father for the sins of the world and in which God's people offer up their lives as a sacrifice to God. It is an action in which the living community of today is united with the Paschal Mystery and brought into direct contact with the saving acts of Jesus Christ. Through all this action and through the power of the priest acting in the name of Christ, Jesus is truly present on the altar, surrounded by the community. As the celebration comes to a conclusion, the community is fed with the divine food and is sent into the world to serve God and to carry out the mission of the Church.