Jesus and the Reign of God in John

What happened to the reign of God when it visited John's world? At first glance, it looks like it got short shrift, appearing in just two verses (John 3:3, 5). However, what if, like the ubiquitous reign of God in the Synoptic Gospels, its two verses are the early planting of a seed that grows and spreads through the book? What if the diction of a parable of God's reign is diffused throughout the text, as is arguably the case with the wildly generous father and his prodigal son? What if the...