The institution of the most holy Eucharist on the evening before the Passion cannot be regarded as some more or less isolated cultic transaction. It is the making of a covenant and as such, is the concrete foundation of the new people: the people comes into being through its covenant relation to God.
We could also say that by his eucharistic action, Jesus draws the disciples into his relationship with God and, therefore, into his mission, which aims to reach "the many," the humanity of all places and of all times. These disciples become a "people" through communion with the Body and Blood of Jesus which is simultaneously communion with God.
The Old Testament theme of covenant, which Jesus incorporates into his preaching, receives a new center: communion with Christ's Body. It could be said that the people of the New Covenant takes its origin as people from the Body and Blood of Christ; solely in terms of this center does it have the status of a people.
We can call it "people of God" only because it is through communion with Christ that man gains access to a relationship with God that he cannot establish by his own power.
Pope Benedict XVI