According to the Catechism of the Catholic Church, the Eucharist is the source and summit of the Christian life. As the sacrament of the body and blood of Christ itself, it is the very heart of the Church from Whom the Church draws all her energy, all her life.
The Body and Blood of Christ
Pope Francis: The Eucharist is our Spiritual Lifeblood
The Eucharist is the spiritual life-blood of the Christian because in receiving it we consume the glorified body of the Risen Lord, whose life transforms us, elevates and empowers us to become like him. Pope Francis noted that in receiving the sacrament of the body and blood of Christ, God communicates interior attitudes of holiness to us, infusing our hearts and minds with his own love and his own thoughts, through the wondrous presence of Jesus and the divine impulses of the Holy Spirit. Among these interior attitudes is “First of all docility to the Word of God.”