The wind{The same Greek word (pneuma) means wind, breath, and spirit.} blows where it wants to, and you hear its sound, but don't know where it comes from and where it is going. So is everyone who is born of the Spirit."

 When John relates conversations that Jesus had with enquirers, he has a way of following a certain scheme. We see that scheme very clearly here. The enquirer says something ( John 3:2). Jesus answers in a saying that is hard to understand ( John 3:3). That saying is misunderstood by the enquirer ( John 3:4). Jesus answers with a saying that is even more difficult to understand ( John 3:5). And then there follows a discourse and an explanation. John uses this method in order that we may see men thinking things out for themselves and so that we may do the same. 