The Youth Catechism (208) describes the sacrament of the Holy Eucharist well:
The Eucharist is the mysterious center of all these sacraments, because the historic sacrifice of Jesus on the Cross is made present during the word of consecration in a hidden, unbloody manner. Thus the celebration of the Eucharist is “the source and summit of the Christian life” (Lumen Gentium [LG], 11). Everything aims at this; besides this there is nothing greater that one could attain. When we eat the broken Bread, we unite ourselves with the love of Jesus, who gave his body for us on the wood of the Cross; when we drink from the chalice, we unite ourselves with him who even poured out his blood out of love for us. We did not invent this ritual. Jesus himself celebrated the Last Supper with his disciples and therein anticipated his death; he gave himself to his disciples under the signs of bread and wine and commanded them from then on, even after his death, to celebrate the Eucharist. “Do this in remembrance of me” (1 Cor. 11: 24).
The Eucharist is the source and summit of our Christian life. It is the source, because in some mysterious way Christ’s sacrifice on the cross is made present, and through that sacrifice He redeemed and reconciled us to God, making all the other sacraments possible at all. And it is the summit because here on earth, if we take the time to realize it, we are getting a glimpse of heaven. If God is Love, and if in heaven we are embraced fully and share in that Love, then in the familiar words of the doxology at the end of the Consecration we glimpse what that might look like. “Through him [Jesus], and with him, and in him; O God, almighty Father”: through Jesus’s death and resurrection, with him by our side, he introduces us into the presence of the Father. “In the unity of the Holy Spirit”: we take a step forward, the Holy Spirit raising us up … “All glory and honor is yours; for ever and ever” … into God’s glory. We look behind us and see God. We look forward and see God. And all around us we see only the unity of Love, which is the communion of God.
“Amen.” So may it be!
“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 upon earth.”
“In the Eucharist we can find all the dimensions of communion: God communicates himself to us, we enter into communion with him, the participants of the sacrament enter into communion with one another, and creation as a whole enters through man into communion with God. All this takes place in Christ and the Spirit, who brings the last days into history and offers to the world a foretaste of the Kingdom.”
John D. Ziziolas