The glory is also evident in the graciousness of this event, as the prologue has prepared us to notice (1:14). In response to a humble request Jesus provides wine in abundance, over 100 gallons. Here is a free, full, extravagant outpouring, and it is precisely the Son of God’s gratuitous, gracious generosity that is the glory revealed in this sign. Throughout the Gospel the signs will provide windows into the ultimate realities at work in Jesus’ revelation of God’s glory, in deed as well as word….
In response to this sign it is said that his disciples put their faith in him (2:11). For John this means that they see what Jesus is doing and understand it, however dimly, in the context of God’s revelation of himself in the Old Testament. They see in Jesus the very acts of power and graciousness that are like his Father’s. Their understanding is very limited, but they see something of the Father in the Son and accept him as one come from God and align themselves with him. This effect of this sign on the disciples is in contrast to the experience of those who most directly reap the benefits””the master of the banquet and the bridegroom. Jesus keeps a very low profile throughout the story with the result that only the servants realize what has happened. How often something similar happens in our lives! God’s grace constantly surrounds us; his love is constantly active in our lives. Yet often we fail to discern his love, seeing only the hands of those who give us the wine and not realizing where it comes from and the grace it represents.
–From his IVP Commentary on John’s Gospel, quoted in this morning’s Adult Sunday School class