When Jesus uses the image of the Bronze Serpent of Moses to show how God will use the Human Being (the son of man)as a cure for our afflictions, he opens up our vocation too as his followers.
The Serpent Story shows that God is merciful and provides the cure. And that is the surprise of the story, we expect God to be vengeful but discover God is forgiving.
In Jesus we discover that as he becomes the cure for business as usual, we are called to see this passage, John 3, as set in God's love of the cosmos - the world. It is not set in the love of the church, but in the love of the world. We don't come to be loved alone, but to go out bearing the light of Christ into the dark.