At the wedding in Cana, Jesus changed water into wine.
The water was in large stone jars used by the Jews used for ceremonial washing. It reminded them of their need for cleansing.
The prophets spoke of a day when the mountains would run with wine (Joel 3:16-18 and Amos 9:13-14). Wine was a symbol of joyous life in God’s presence.
By turning the water of cleansing into wine Jesus was demonstrating that the Old Testament system of purification was now being replaced with the blessings of the new age being poured out. (c.f. the prophets).
The day of God’s great wine has arrived and Jesus is the winemaker.
The gospel is new wine that must now be contained in new wineskins, that is, Jesus’ teaching of the kingdom and its joy.