John's gospel often refers to Jesus' miracles as signs to show us that they are not merely bursts of power, not merely meant to cause wonder and awe. Both of those are used in John and in the other gospels to describe Jesus' signs and wonders and acts of power. But John focuses on signs because he knows that these miracles point beyond themselves. The turning of the water into wine points beyond simply the provision at a wedding feast to spare embarrassment for those who should have stocked more wine. It's really a signal that the messianic feast prophesied in Isaiah 25 is beginning. Or very obviously, the feeding of the five thousand, as Jesus multiplies the bread, leads Jesus right into a lengthy discourse in which he shows that the bread that we eat and ingest in our bodies feeds us only briefly, but the Father is giving true, life-giving, eternal life-giving bread from heaven and that Jesus himself is that bread of life. Or again, the resurrection of Lazarus. Lazarus is raised from the dead, physically restored to life in this world, but Jesus says to Martha, really what this sign is pointing to is that Jesus himself is the resurrection and the life. And earlier in John's gospel, John 5, Jesus speaks of the present day being the day when people hear the voice of the Son of God — dead people come to life. That's the Spirit's life-giving power in bringing people to faith and life in God through the gospel. And the day will come when all who are in the graves, who are physically dead, will emerge, either to face judgment if they've not believed in the Son, or to enjoy eternal life because the Son gives life.