Holy Communion augments our union with Christ. The principal fruit of receiving the Eucharist in Holy Communion is an intimate union with Christ Jesus. Indeed, the Lord said: “He who eats my flesh and drinks my blood abides in me, and I in him.” Life in Christ has its foundation in the Eucharistic banquet: “As the living Father sent me, and I live because of the Father, so he who eats me will live because of me.”
On the feasts of the Lord, when the faithful receive the Body of the Son, they proclaim to one another the Good News that the first fruits of life have been given, as when the angel said to Mary Magdalene, “Christ is risen!” Now too are life and resurrection conferred on whoever receives Christ. What material food produces in our bodily life, Holy Communion wonderfully achieves in our spiritual life. Communion with the flesh of the risen Christ, a flesh “given life and giving life through the Holy Spirit,” preserves, increases, and renews the life of grace received at Baptism. This growth in Christian life needs the nourishment of Eucharistic Communion, the bread for our pilgrimage until the moment of death, when it will be given to us as viaticum. – Catechism of the Catholic Church 1291-1295