Out of the darkness of my life, so much frustrated, I put before you the one great thing to love on earth: the Blessed Sacrament..There you will find romance, glory, honour, fidelity, and the true way of all your loves on earth."
- J.R.R. Tolkien
The Eucharist is one of the Sacraments of Initiation (along with baptism and confirmation). Often called 'communion,' the Eucharist is the very source of our entire lives as Catholics. We say that because the Eucharist really is the body, blood, soul, and divinity of Jesus Christ. This is not just a symbol. In the Sacrament, the very essence or substance of the bread and wine is completely changed. Because the Eucharist is Christ Himself, we say that the Eucharist is "the source and summit" of the Christian life.
The Gospels of Matthew, Mark and Luke all give accounts of the Last Supper. Let's listen to His words:
"While they were eating, Jesus took bread, said the blessing, broke it, and giving it to His discipes said "Take and eat; this is my body." Then He took a cup, gave thanks, and gave it to them, saying "Drink from it, all of you, for this is my blood of the covenant, which will be shed on behalf of many for the forgiveness of sins." - Matthew 26:26-28
More on the Eucharist, from the Catechism HERE.