Well, we can see what it is doing to the trees and the direction it appears to be pushing them.
As an unseen force, I like the image of wind as the breath of God, or the Holy Spirit. The third Person of the Trinity, the Holy Spirit, might be the hardest one to understand, but it is the one which gives understanding, power and life itself.
I don't particularly like the image of the Holy Spirit as a dove. In the Genesis account of creation, the Spirit of God existed with the Father and the Son (the Word) in the Beginning:
'Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the water.' (Genesis 1, verse 2)This is the only occasion, I think, when the Spirit is described as being in a waiting and apparently motionless state, but I suppose 'hovering' does imply a bird-like activity. The Hebrew word used here for 'Spirit' can also be translated (and is elsewhere in the Old Testament) as 'Breath' or 'Wind'. So in the creation account of Adam, ' the Lord God formed the man from the dust of the ground and breathed into his nostrils the breath of life'. In Job 33, verse 4, Elihu says to Job, 'The Spirit of God has made me; the breath of the Almighty gives me life.'
Of course the New Testament gives us the whole picture of the Holy Spirit, not only in the Pentecostal experience of wind and tongues of fire at the birth of the church, but before (in the teachings and promises of Christ), and after (in the teachings and experiences of the Apostles).
I used to think of the Trinity as being the same thing in 3 different forms - a bit like water being liquid (normal water), solid (ice) or gas (steam), but the parallel breaks down if it is taken too far, and stops being helpful. Sometimes you can hear a hymn sung hundreds of times before particular words strike home with a new understanding. This happened recently to me with the hymn "Breath on me, Breath of God. Fill me with life anew." At the same time I came across Jesus' own illustration of the Holy Spirit as being like the wind in John 3, verses 6-8:
'Flesh gives birth to flesh, but the Spirit gives birth to spirit. You should not be surprised at me saying, "You must be born again." The wind blows wherever it pleases. You hear its sound, but you cannot tell where it comes from or where it is going. So it is with everyone born of the Spirit.'We are all control freaks as far as being in control of our own destiny is concerned. It is hard to trust and obey an unseen God when it means letting go and sailing in faith with the Wind. But if I don't and just drift along with the earth's flow, where will I end up?
Yes the question deepens, and we have all the gifts of the Spirit, baptism of the Spirit and so on. But then the denominational wrangles emerge and create a storm of their own. I think it's best to keep it simple so that you can actually feel the breeze that is directed at you.