From He Who Gives Life by Graham Cole:
In his celebrated encounter with Nicodemus, Jesus makes a crucial point about the elusiveness of the Spirit (John 3:3–8). Jesus said that the Spirit’s action is like that of the wind. The movements of the wind have a mystery to them. You can’t tell where the wind comes from or where it is going. Likewise the Spirit. Indeed the Spirit blows where he wills. No one is master of the Spirit. As John Goldingay points out with regard to both Old and New Testaments, “Wind suggests something of the mysterious, invisible, dynamic power of God.”
Nicodemus should have known such things, according to Jesus (John 3:10). After all he was a teacher of Israel, a learned Pharisee and community leader. He presumably knew his Scriptures. Perhaps Jesus had in mind that scene in Ezekiel where the valley of dry bones comes alive through the mighty wind of God blowing through it (Ezekiel 37). A whole people needed to be born again. But all Jesus’ talk of being born from above or again had passed Nicodemus by. He simply did not get the thrust of the metaphor and was thinking in crass, all too literal categories. How could man enter his mother’s womb and be born a second time (John 3:4)? It made no sense.
Anyone writing about God in general and the Spirit of God in particular needs to reckon with mystery. As George S. Hendry suggests, “The true doctrine of the Holy Spirit will always be one that recognizes the inherent subtlety and complexity of the subject and is most conscious of its inadequacy to grasp the mystery after which it gropes.”
Bernard Ramm was aware of the difficulty of writing about the Spirit when he commented, “To profess to know a great deal about the Spirit of God is contrary to the nature of the Spirit of God. There is a hiddenness to the Spirit that cannot be uncovered. There is an immediacy of the Spirit that cannot be shoved into vision. There is an invisibility of the Spirit that cannot be forced into visibility. There is a reticence of the Spirit that cannot be converted into openness. For these reasons one feels helpless, inadequate, and unworthy to write a line about the Spirit.”