While I entertain you with word games, maybe you could provide the following:
• Scriptural proof that Jesus is God and the Holy Spirit is God
At the risk of repeating myself...
"I and my Father are One" proves the first, and the second is a non-sequitor. (My arm is part of me, and God's Spirit is a part of God)
• Scriptural proof that God consists of the Father, the Son and the Holy Spirit; three persons in one being (i.e. "three hypostases (or divinities) in one ousia", for those Trinitarians who cling to the traditional formula)
Hypostasis doesn't mean person (or even personae), and Ousia doesn't mean Being, so this formulation is more of a mistranslation than anything else.
Proving that the Father is God seems easy, since He's regularly called "Father God" in Scripture.
Proving that the Spirit of God is God also seems rather simple. Why else would He be called 'the Spirit of God,' if He were not God?
Proving that the Son is God is less straightforward, but not that difficult, in light of statements such as "before Abraham was, I AM." The NT also quotes the OT ascribing the names "wonderful counselor, mighty God, and even everlasting Father" directly to Jesus.Ousia
translates as essence, form, shape, or image.
In Platonism it denotes a Platonic form. The highest form in Platonism is the Form of the Good, and all other Forms derive from it. All the forms then are heavenly, an belong to the realm of the intellect. Hypostases
("that which stands beneath") are things here in the real world which typify the celestial forms. If I have an apple, for instance, it may be a hypostasis of several forms ("red" "delicious" "nutritious" "good").
Now, the OT teaches that God Himself is "most high" and that He cannot be fully comprehended ("invisible God"). That is, He is a transcendant intelligence, and not a corporeal being. Christianity, being born into a culture where Greek language was the medium of communication, used the word Ousia to express the same.
Throughout the OT, the Bible puts forward that we can know God through His attributes, which if we put it into the Greek nomenclature, would be Enthymeses
(expressed attributes, or emanations). That is, we may not understand everything of the mind of God, but we can know His mercy. Or His longsuffering. Or His judgment. Or His truthfulness. Hence the many names of God throughout the book. He is Jehova Rapha, Jehovah Jaira, Jehova Sabaoth, Jehovah _____.
Moreover, the Bible uses the word Pleroma (fulness) to talk about ALL of God's attributes (or emanations, if you will), jointly.
The gnostics, blending Platonism and other Greek philosophy with Judaism and Christianity however they saw fit, takes the concept to a logical extreme, anthropomorphizing the forms, and then exalting them as being the gods. In gnosticism, the highest form, or ousia, is generally regarded as the highest deity of that religion (for example, Bythus for the Valentinians), and the rest of their "pantheon of gods" are not independent deities, but rather derivations of the attributes of that ultimate god. For example, they may have a deity of light (photos), but it is understood that light is only an attribute of the higher deity. They go on to eventually denounce everything material (all hypostases) as being imperfect and thus evil.
Thus it is that the apostle Paul devotes an entire book - Colossians - to clearing up misunderstandings on this subject caused by gnostic teachings.
Paul is clear in showing that Jesus is material, and existed here below "in the flesh" (refuting the gnostic teaching that Christ was not here materially). Colossians 1:15 says that Jesus is "the eikon of the invisible God." Eikon (or icon), is the same word the NT elsewhere translates as "idol." Paul is saying that while God Himself belongs to the realm of the celestial, He has provided Jesus as His exact image - His exact Form - in a material representation here on earth. As the heathens' idols of wood and stone were mere representations of the powers they really worshipped, so was the man Jesus the representation of the One True God.
Paul further shows that Jesus is not merely one aspect (enthymesis) of the Godhead expressed, as the gnostics taught Him to be one attribute of the Godhead, but rather that He is the representation of ALL the attributes. Col 1:19 "For it pleased the Father that in him should all the Pleroma (fulness) dwell."
Understanding the words, then, leads one to read the early creeds differently. The Father is transcendant, He is a Mind and not a body. He cannot be a hypostasis Himself. Jesus was the hypostasis of the ousia of the Father - the Son, we say, for the Mind has begotten the Word, and the Word is what has come to us in the flesh. Fast forward, and the church is the hypostasis. The church is the body
As to the Spirit of God which "proceeds from the Father," it is evident that It is that part of God which carries the thoughts from the Mind to the Body. One cannot make it a Mind unto Itself. Note:
When he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, [that] shall he speak: and he will shew you things to come. (John 16:13)
So I do not find the early church in error. I do find the later, Latin church, did a poor job of understanding and translating the Greek.
As for myself, I believe in the Father, and the Son, and the Holy Ghost, and I understand there to be but One God, transcendant above all, and One Lord, the Son, the hypostasis of the pleroma of this same One God, and One Holy Spirit, the Spirit of that One God by which the divine Mind communicates His Word to His body, and One Church, which is that body and the primary means by which God acts here below.
So call me a trinitarian, or not a trinitarian. I've been accused of both. I will take the truth, and let the rest fall where it may.