God is a Spirit: and they that worship him must worship him in spirit and in truth.
All Commentaries on John 4:24 Go To John 4
Gregory The Dialogist
AD 604
And again, if the impious say, How will there not be three Gods and three Persons, on the supposition that they have one and the same divinity?-we shall reply: Just because God is the Cause and Father of the Son; and this Son is the image and offspring of the Father, and not His brother; and the Spirit in like manner is the Spirit of God, as it is written, "God is a Spirit.".
For thus the Father is Lord, and the Son also is God; and of God it is said that "God is a Spirit."
