The Greek word means compressed air. It moves rapidly and has a sound. Is "pneumatic" the correct definition for, say, an Angel? The Spirit mentioned in Genesis 1:2 is also defined as moving air. There's the idea of a rushing wind. Is moving air the basic essence of such things? What about God being a consuming fire? Does fire mean the idea of burning wood or paper? What if it means electricity, as in lightning? Air, by contrast, if powerful enough to do something, would have to be something like a giant tornado.
The words are spirit, foolishness (by design) to the natural man. The spiritual meaning of the words must be understood in parable, where th
e object of the parable is not the
subject, and requires spiritual discernment. In this way, "
My sheep hear my voice", means the other animals cannot...which is done on purpose. That purpose being the dividing of the sheep from the goats, and the wheat from the tares, and light from darkness.
But that is simply an explanation, not an answer key to the word of God. There is no easy grade given out in the halls or on the corner. It begins by hearing, and hearing by the word of God. More study. More listening.
Meanwhile, more questions are cool. People who know God and His ways are big on love - not good at it, but we do prefer it. Welcome. Stick around!