TRINITY

Internet Archive: Athanasius_Letters_to Serapion... The introduction to the false god "godhead" takes away three identities and makes them one.

• Coining the Term (Early 3rd Century): The Latin theologian Tertullian was the first to use the word Trinitas (Trinity). He introduced the formula "one substance, three persons" (una substantia, tres personae) to explain that while they are distinct in role or "form," they are one in "spiritual matter".
• The "Same Substance" (325 AD): At the Council of Nicaea, the Church adopted the term homoousios ("of the same substance") to declare that Jesus was not a separate created being but was equal to the Father.
• The Final Definition (381 AD): The Cappadocian Fathers (Basil the Great, Gregory of Nyssa, and Gregory of Nazianzus) resolved the remaining confusion by distinguishing between Essence (ousia) and Person (hypostasis). They argued:
  • Essence: What God is (one divine nature).
  • Person: Who the Father, Son, and Spirit are (three distinct ways of being that one nature). 

The transition from debate to state-enforced punishment—including excommunication, exile, and eventually execution—occurred in stages between 325 AD and 385 AD. While the Council of Nicaea introduced excommunication and exile as tools for unity, it was not until the late 4th century that the Roman state began using capital punishment for theological dissent.

The creed was amended by the First Council of Constantinople in 381.

1. Jesus Christ is described as "Light from Light, true God from true God," proclaiming his divinity.
2. Jesus Christ is said to be "begotten, not made," asserting that he was not a mere creature, brought into being out of nothing, but the true Son of God, brought into being "from the substance of the Father."
3. He is said to be "of one substance with the Father," proclaiming that although Jesus Christ is "true God" and God the Father is also "true God," they are "of one substance." The Greek term homoousios, consubstantial (i.e., of the same substance), is ascribed by Eusebius of Caesarea to Constantine, who, on this particular point, may have chosen to exercise his authority. The significance of this clause, however, is ambiguous as to the extent in which Jesus Christ and God the Father are "of one substance," and the issues it raised would be seriously controverted in the future.

Exiled & Murder

• • The First Council of Nicaea concluded by excommunicating Arius and two Libyan bishops who refused to sign the Creed.
  • Emperor Constantine enforced the Nicene Creed by banishing them and ordering Arius's writings to be burned. He even threatened death for anyone caught hiding Arius's books, though there are no verified records of executions for this specific offense at that time.
• 335–380 AD: Political Volatility and Banishments
  • For several decades, the "official" view shifted depending on the sitting Emperor. Athanasius, the champion of the Trinity, was himself excommunicated and exiled five separate times as Arian-leaning emperors gained power.
  • During this period, violence was often localized and physical, involving riots or the forceful removal of bishops from their cathedrals rather than formal state executions.

The emperor carried out his earlier statement: everybody who refused to endorse the creed would be exiled. Arius, Theonas, and Secundus refused to adhere to the creed and were thus exiled to Illyria, in addition to being excommunicated. The works of Arius were ordered to be confiscated and consigned to the flames,^[66] while his supporters were considered "enemies of the new Christianity."^[67] Nevertheless, the controversy continued in various parts of the empire.

EMPERORS GRATIAN, VALENTINIAN, AND THEODOSIUS AUGUSTI. EDICT TO THE PEOPLE OF CONSTANTINOPLE.
It is our desire that all the various nations that are subject to our Clemency and Moderation, should continue to profess that religion which was delivered to the Romans by the divine Apostle Peter, as it has been preserved by faithful tradition and as it is now professed by the Pontiff Damasus and by Peter, Bishop of Alexandria, a man of apostolic holiness. According to the apostolic teaching and the doctrine of the Gospel,

Let us believe in the one deity of the Father, the Son, and the Holy Spirit, in equal majesty and in a holy Trinity.

We order the followers of this law to embrace the name of Catholic Christians; but as for the others, since, in our judgment, they are foolish madmen, we decree that they shall be branded with the ignominious name of heretics and shall not presume to give to their conventicles the name of churches. They will first suffer divine condemnation and then the punishment of our authority, which we shall inflict according to our will.