Former Archbishop of Canterbury and Anglican theologian Rowan Williams:
So as we give thanks over bread and wine in the presence of the Lord we are – with him and in him – seeking to make that connection between the world and God, between human experience and the divine and eternal Giver. And that means that we begin to look differently at the world around us. If in every corner of experience God the Giver is still at work, then in every object we see and handle, in every situation we encounter, God the Giver is present and our reaction is shaped by this. That is why to take seriously what is going on in the Holy Eucharist is to take seriously the whole material order of the world. It is to see everything in some sense sacramentally. If Jesus gives thanks over bread and wine on the eve of his death, if Jesus makes that connection between the furthest place away from God, which is suffering and death, and the giving and outpouring of his Father, and if in his person he fuses those things together, then wherever we are some connection between us and God is possible. All places, all people, all things have about them an unexpected sacramental depth. They open on to God the Giver.
And that is why many Christians have found that in reflecting on the Eucharist they begin to see what a Christian attitude to the environment might be. Do we live in the world as if God the Giver were within and behind and in the depths of every moment and every material thing? Well, no, for most of the time we do not. We live on the surface, we see what suits us and serves our goals – as if, instead of having their own depth and integrity, things are just there for us to exploit and abuse. Reverence for the bread and the wine of the Eucharist is the beginning of reverence for the whole world in which the giving of God’s glory is pulsating beneath the surface of every moment.
That is also why, although this sometimes has been a controversial element in Christian history, reverence for the bread and the wine has instinctively been felt to be a good thing, something appropriate to Christians. It is why the Book of Common Prayer tells you that you need to consume reverently at the end of the Holy Communion what is left over. Here is something of the world that has been identified as carrying the power and love of God to you. Don’t just throw it away. Make what you will of this tradition of reverence for the consecrated things; but it does at least suggest that to take seriously the material food of the bread and wine can be the beginning of a proper and grateful reverence before all God’s material things – a doorway into seeing all things as demanding reverent attention, even contemplation.
– Being Christian: Baptism, Bible, Eucharist, Prayer