The Holy Spirit is normally invisible with exceptions for the faith of humans. He has appeared as a Dove and as tongues of fire, as a wind and usually, he is seen in his effects. Like the trees bending to the wind. Most often he is felt, sometimes as a sensation, but mostly as a heartfelt whisper. A nudging forth to do something, and if you resist will be persistent. To hear or feel him you must have a connection to your heart. We as humans build up walls around our hearts to protect us from harm, but this places a barrier between us and God too.
We are born dead to God, a physical shell with a soul, a mind, and a will. We were meant to co-exist with God's Holy Spirit. A third part of us connects us to God. Adam had this connection before he lost it to sin. It is the Holy Spirit that redeems us, when we accept Jesus as our King, he sends the Holy Spirit to infill us to be the temple of God. While the Children of God exhibit the seven Spirits of God's touch, the greatest gift is the connection to Jesus, God the Father through the Holy Spirit. We become one with God, influenced by God, but we are only a mirror of something greater.