If spirits are in many ways like birds then there is one bird greater than all other birds and more ancient like an ancient dinosaur of a bird and this is a way the Holy Spirit can show what He is like. He came as a dove upon the baptised Messiah, Jesus of Nazareth as The Father from heaven by His Angel spoke to testify that Jesus is His Beloved Son. He can be like a huge bird of dinosaur proportions and ancient eternal life to show He is greater than any spirit in this world. Having Him as someone you know at your side is triumphant and a mighty comfort. Even His offspring made by His power as disciples of Lord Jesus are huge baby birds even if the haven't learned to fly yet. That which is born of Spirit is spirit.
