§787
Creed › … › Paragraph 2. the Church - People of God, Body of Christ, Temple of the Holy Spirit
The Church is communion with Jesus
From the beginning, Jesus associated his disciples with his own life, revealed the mystery of the Kingdom to them, and gave them a share in his mission, joy, and sufferings. Jesus spoke of a still more intimate communion between him and those who would follow him: "Abide in me, and I in you.... I am the vine, you are the branches." and he proclaimed a mysterious and real communion between his own body and ours: "He who eats my flesh and drinks my blood abides in me, and I in him."
Source: Catechism of the Catholic Church (Vatican.va)