It’s important here to distinguish here between the Trinity, (as in the Father, the Son, and the Holy Spirit), and the doctrine/nature of the Trinity (i.e. three consubstantial separate persons).
Greetings gazelam

I agree it is important to distinguish the faith in the Trinity, and when the Trinity is defended against heretics at a later time. The Trinity became a doctrine binding upon all believers in order to protect the flock of Jesus Christ from false shepherds and heresy.
Let us be clear here; The Catholic never goes out of her way to invent some new idea and to declare a new revelation with a doctrine. When the Catholic Church declares a doctrine. She exercises her divine Keys to bind and loose upon the whole earth, in order to protect and defend the revelations of Jesus Christ and the Apostolic faith handed down to us.
**I disagree with your new idea of the Trinity consisting of “three consubstantial separate persons”. **
The Catholic Church never teaches that the Trinity is “three consubstantial separate persons”.
The Trinity of persons are distinct in presence, never separated or divided or confused.
It would appear you are forcing a carnal understanding of persons and contradicting it with the presence of God. Your “separated persons” is a contradiction to God’s presence and God’s Essence. More on this later.
But to say that the nature as defined in the Nicene Creed of the Trinity is a matter of Apostolic Faith is incorrect
I believe you misunderstand and take my position out of context here. Faith in the “NAME” **singular **Father, Son, Holy Spirit, is an apostolic faith and divine revelation from Jesus Christ. The Church in her infant stage, had no reason to defend the Trinity, because for the first three hundred centuries it was always a matter of divine revelation and faith.
The Trinity as I stated above, becomes binding upon all believers, when this apostolic faith in the Trinity came under attack by heretics. The apostolic faith in the Trinity has never changed.
What has developed is a understanding and clarification of the Trinity that defeats heretics who opposed or try to change with carnal understanding of the Trinity. Let me be clear here, that clarification made by the Church councils never exhausted or definitively defined the Trinity. The doctrine of the Trinity only separates the flock of Jesus Christ from wolves or false shepherds.
Here are three quotes that show that the current doctrine of the nature of the Trinity is a (man-made IMHO) development:
The Trinity is a divine revelation of God which no man can never define in a single definition. Trinity is a matter of apostolic faith revealed by divine revelation. Trinity is never man made.
The understanding and developed understanding of the Trinity enters history when the Church has to defend the already believed in Trinity against new man made winds of doctrine that have come and gone.
B]The New Testament itself is far from any doctrine of the Trinity or of a triune God who is three co-equal Persons of One Nature.
(William J. Hill, The Three-Personed God (Washington DC: The Catholic University of America Press, 1982), 27.)
The New Testament never records any doctrine. The quotes you have introduced makes a false argument against the subject matter being discussed here.
Your quotes only support my view, that the apostolic faith in the Trinity never comes under attack during the recording of the New Testament, thus
the Church never has cause to declare a doctrine by exercising her divine Keys of binding and loosing the Trinity against heretics or heresies, in the time frame, your quoted authors mention.
[Origen said that the nature of God was unknown in his day. "**For it is also to be a subject of investigation how God himself is to be understood, – whether as corporeal and formed according to some shape, or of a different nature from bodies, – a point which is not clearly indicated in our teaching, and the same inquiries have been made regarding Christ and the Holy Spirit
". (The Anti-Nicene Fathers 4:241)
You misunderstand Origen here. What Origen teaches is in agreement with all other early Church Fathers, that “God’s Essence never comes down to us”, I believe, I am quoting St. Hillary here? Origen is teaching what the Catholic Church still teaches today unchanged. For any man to see God as God is, man would surely die.
So Origen’s statement shows that the nature of the Trinity wasn’t something just happily passed down from Apostle to Bishop and accepted carte blanche by everyone. It seems a stretch to argue that the doctrine of the Trinity was a matter of Apostolic faith since it was not taught by either the Apostles, nor the Apostolic fathers.
No, Origen discusses the distinction of God’s presence and God’s Essence “which does not come down to us”. Origen defends the already believed in NAME, Father, Son, Holy Spirit, which is practiced in every valid baptism.
Now what you are arguing, is that these early Church fathers do not declare the Title Trinity as doctrine. This comes later when Tertullian and Origen’s faith in the Trinity comes under attack. The Church defends their apostolic faith when she declares the Trinity as binding upon all believers. If one did not accept the apostolic faith in the now declared Trinity, “let them be anathema”. This is the exercising of the Church’s Keys, Jesus gives her to preach, teach and defend God’s revelation to our humanity.
Do you understand Origen, Tertullian’s teachings on the Nature, presence, Essence of God? Their teachings all fall in line perfectly with the declared doctrine of the Trinity.
Peace be with you