God IS Spirit - not "a" spirit. Big difference.
"God is a Spirit: and they that worship him must worship him in spirit and in truth." - John 4:24
"But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his." -- Romans 8:9
"For what man knoweth the things of a man, save the spirit of man which is in him? even so the things of God knoweth no man, but the Spirit of God." -- 1 Corinthians 2:11
"Now we have received, not the spirit of the world, but the spirit which is of God; that we might know the things that are freely given to us of God." -- 1 Corinthians 2:12
"Hereby know ye the Spirit of God: Every spirit that confesseth that Jesus Christ is come in the flesh is of God:" -- 1 John 4:2
I Am that I AM<(¿)>