Just for funsies, here's one more. St Clement of Rome was born c 35 and became the Bishop of Rome in 88 AD. He died 99 AD. There are several epistles attributed to St Clement that are spurious, but the Epistle to the Corinthians is considered genuine (even by Ehrman, for what it's worth).
As a background, c58 AD we think St Paul wrote his letter to the Romans. St Clement would have been around 25 when St Paul's epistle made it to Rome, and around 30 when St Paul was martyred. St Clement was either the second or third bishop of Rome after St Peter, and by any account he knew and was appointed by St Peter personally.
This letter is considered to have been written around 96 AD (but perhaps as early as 80 AD). In it, St Clement repeatedly identifies that the Holy Spirit is the voice of prophecy (e.g., "Look carefully into the Scriptures, which are the true utterances of the Holy Spirit"). This is unsurprising, but the more interesting fact is the linking of the Holy Spirit to the person of Jesus Christ -- for example, he says "Now the faith which is in Christ confirms all these [admonitions]. For
He Himself by the Holy Spirit thus addresses us". How could something that was not, speak before it was?
We also see the common Trinitarian formulation: "For, as God lives, and as the Lord Jesus Christ and the Holy Ghost live..." Clearly we have three divine persons, yet one God, because St Clement also writes "Have we not [all] one God and one Christ? Is there not one Spirit of grace poured out upon us? And have we not one calling in Christ?"
St Clement even carefully notes the difference between the birth of Christ according to the flesh "From [Abraham] also [was descended] our Lord Jesus Christ according to the flesh." This difference is amplified by the use of the proof text of Trinitarian divine generation (bold and italics) later, when St Clement writes:
Quote:
This is the way, beloved, in which we find our Savior, even Jesus Christ, the High Priest of all our offerings, the defender and helper of our infirmity. By Him we look up to the heights of heaven. By Him we behold, as in a glass, His immaculate and most excellent visage. By Him are the eyes of our hearts opened. By Him our foolish and darkened understanding blossoms up anew towards His marvelous light. By Him the Lord has willed that we should taste of immortal knowledge, who, being the brightness of His majesty, is by so much greater than the angels, as He has by inheritance obtained a more excellent name than they. Hebrews 1:3-4 For it is thus written, Who makes His angels spirits, and His ministers a flame of fire. But concerning His Son the Lord spoke thus: You are my Son, today have I begotten You. Ask of me, and I will give You the heathen for Your inheritance, and the uttermost parts of the earth for Your possession.
All of the bolded portions are common in Trinitarian understanding of Christ - He has the Light of God, being God.
The letter references Father, Son, and Spirit as God interchangeably, as one would reasonably expect someone with a belief in the Trinity to do.
Interestingly enough, St Clement also uses a phrase that St Maximos, St Dionysius the Areopagite would later discuss quite a bit, that we are "portions of" Christ ("Seeing, therefore, that we are the portion of the Holy One...). I never noticed that before. Neat.
Ehrman is suggesting that by not having a rigorous definition of the doctrine the underpinning beliefs effectively didn't exist. This is similar to arguing that people didn't know they would fall down before Newton rigorously defined gravity.
And even Ehrman notes this, that the idea that there are Three but only One is as old as the Faith. What he's conflating in that video is a couple of different doctrines - that of the Incarnation of the Word, the Trinity, and later Christological doctrines (e.g., the dual nature of Christ). This has nothing to do with a belief in the Trinity.