...is that they represent how we’re to live every aspect of our lives.
In the first
place bread and wine require a gift from God in wheat and grapes. We
can’t “make” these ourselves. On the other hand we have to grind the
wheat and press the grapes and go through plenty of other steps to get
bread and wine. This is why they’re referred to as “fruit of the land and work of human hands”.
This is a pattern for everything in our lives. God gives us a gift, we
take it and work with it, and then we offer it back to him. For
example, our ability to work is a gift which we must nurture, hone, and
do our best with. The results of God’s gifts and our efforts (most
noticeably a paycheck) then should be offered back in thanksgiving
(which is where tithing “first fruits” comes from).
in our lives is like this; up to and including life itself. Our very
life is a pure gift which we can choose how to use. The bread and wine
of the Eucharist remind us that we’re called to give God the first
fruits of our very lives—our mind, heart, and strength—to serve him.
Following this simple model will surely lead us down the path of being
good and profitable servants (Mt 25:21); which is all we could ever hope
This is yet another reason Catholics use bread and wine for Communion.