So is it in the realm of the Spirit. You cannot see the Spirit - as Jesus said, "It is like the wind. You don't know where it comes from or where it goes." You can see the effect but not the invisible Spirit.
This same Holy Spirit enters into mere mortal men and women. When this happens there is a resultant visible explosion of grace, love and praise. Humans are changed in an instant and this new life rushing into the vacuum of their lives begins to express itself (or Himself) through these vessels - these people. They begin to react to or manifest this new life by selling homes and giving the money away to the needy - being in one accord - loving each other unconditionally - sharing their possessions - prophesying - and speaking with tongues (to name a few). These are not "the Spirit" but are simply visual EFFECTS or the REACTION to the coming of the wind of the Spirit.
I find it interesting that our Lord promised, "You shall receive power (dunamis) when (after that) the Holy Spirit has come upon you..." Power is translated from the Greek word dunamis. It is from this word that we derive our English word dynamite.
From the invisible to the visible. A divine explosion.
"If I speak with the tongues of men and angels and have not love I am nothing. If you sell everything - EVERYTHING and give to the poor but I have not Agape (love) my profit is a big fat ZERO!"