It seems (at least to me who has never had to organise a wedding) that it is the wedding feast, not the wedding, that takes by far the most trouble to arrange. It is not simply nourishment for the guests.
The major part of the celebration is the feast and there are often more traditions associated with it than with the ceremony itself: photographs, for example; the ritual of welcoming; who gives speeches and in what order; the first dance. I'm sure you can think of many others.
What this suggests is that a wedding is about rejoicing. It is mandatory to rejoice, for this reflects the relationship between the spouses: the newlyweds rejoicing in each other. So the very idea of a wedding includes the feasting. It is ironic, then, that rejoicing is often the last thing that we feel like doing under the pressure of providing such a celebration, or the pressure of being nice to family, or of talking to people we don't know. Wine becomes essential in these situations.
Nevertheless, we learn from Isaiah's image that the relationship of God to his people is like that between bridegroom and bride: 'as the bridegroom rejoices in his bride, so will your God rejoice in you' (Is. 62.5). God's relationship with Israel is not simply as husband to wife, as St Paul's images duly emphasise, but as the newly married - for God is never changing, always new.
'On the third day there was a marriage at Cana in Galilee' (Jn 2.1). But the rejoicing at Cana has hit a snag in John's Gospel, which is, of course, a cause of great shame for the hosts. Wine is linked to joy, just as bread is linked to nourishment, and without wine, who can rejoice and partake of the joy of the newlyweds? Wine is the sign of our joy, that a meal becomes a feast, that sustenance becomes eternal rejoicing - the work of God.
'On this mountain the Lord of hosts will make for all peoples a feast of fat things, a feast of wine on the lees, of fat things full of marrow, of wine on the lees well refined' (Is. 25.6). And this is the first sign of Jesus: that, on the third day the Lord provides the joy for the feast. Jesus manifests his identity with God, the bridegroom of Israel, and his union with humanity. The miracle of Cana is the sign of God's abundant rejoicing. It manifests the kingdom, God's sovereignty, in exuberant feasting. It shows that the bridegroom is with his bride and rejoices in her.
'Can the wedding guests fast while the bridegroom is with them?' (Mk 2.19)… When Jesus completes his answer to the Pharisees with a warning that the bridegroom will be taken away, so the shadow of the cross falls over this newest of new wines.
'This is my blood of the covenant, which is poured out for many. Truly, I say to you, I shall not drink again of the fruit of the vine until that day when I drink it new in the kingdom of God' (Mk 14.24-25). His passion, his glory, his 'hour' pervades everything Jesus does, hence his response to his mother: 'my hour has not yet come'. For any symbolic act of Jesus will be a sign of Calvary. The marriage of God and man in Christ is an epiphany of our salvation, but it is shown forth most clearly in the cross. The feast given to us in the Mass foreshadows that banquet on God's mountain, but it is also the making present of the Lamb's sacrifice.
The new wine of God's kingdom is only reached through the shedding of blood - but there will be abundant rejoicing, and the raising of a glass… on the third day.
'…What said You then to trembling friends and few?
"A moment, and I drink it with you new:
But in my Father's Kingdom." So, my Friend,
Let not Your cup desert me in the end.
But when the hour of mine adventure's near
Just and benignant, let my youth appear
Bearing a Chalice, open, golden, wide,
With benediction graven on its side.
So touch my dying lip: so bridge that deep:
So pledge my waking from the gift of sleep,
And, sacramental, raise me the Divine:
Strong brother in God and last companion, Wine.'