History of the Doctrine Concerning the Nature of God
In the early centuries of Christianity
Logos-Christology, the root of Arianism and Trinitarians
In the second century, at Alexandria, Egypt, with its great Universities, libraries, learned professors and throngs of eagerly Inquiring and active-minded students — where the Hebrew philosophy of Philo and the greek teaching of Plato had blended with the doctrine of Moses and the prophets for a modified teaching of contemporary thought — the first serious attempt was made by Christians to adjust the facts And truths of the gospel and the relations of Christian doctrine to Reason and philosophy. 
This modified philosophy which resulted in a concept of a human Christ, called “logos-Christology,” ran to seed in what is known as “arianism” and was in opposition to the dominant sabellian Tendencies.  and yet logos-Christology was also to be defined as a Doctrine of the trinity — not the anathanastan, Trinitarians, to be Sure, but the forerunner of it. 
The historic doctrine of the trinity contains two elements, Representing two and interests: the pre-Existence of the son of god incarnate in Jesus Christ, and the full Deity of this pre-existent son of god. The former is known as the Logos-Christology and by the end of the third century (in the form of Arianism) had overcome monarchianism  (which emphasized that the Deity of the messiah was the one true god, the Jehovah Elohim of the Old testament, the god of Abraham, Isaac and Jacob).
Tertullian’s most influential work was the definition of the : “all are of one, by unity of substance; while the Mystery of the dispensation is still guarded which distribute the unity Into a , placing in their order the three, the father, the Son, and the holy spirit…”
The great advocate of logos-Christology was Hippolytus, 167-235, The most learned Christian writer then in the city, a highly reputed Commentator, chronicler, calculator of the Easter dates, apologist, and Opponent of heretics.
Hippolytus vigorously opposed the monarchians, whose chief tender Was noetus of smyrna. The fight in rome waxed so hot that bishop Zephyrinus (198-287) hardly knew what to do, though he leaned toward The monarchian side. His successor, kallistos (calixtus) (217-222), The most energetic and assertive bishop that rome had yet seen, Excommunicated sabellius (who continued monarchianism previously Defended by noetus). He also charged hippolytus with being a Worshipper of two gods. Kallistos, formula>, asserted that father, son, and logos are all indivisible spirit>. Yet son is also the proper designation of that Which was visible; Jesus, while the father was the spirit in him. This
Presence of the father, after he had taken unto himself our flesh, Raised it to the nature of deity, by bringing it into union with Himself, and made it one, so that the father and son must be styled one God.
This compromise won the majority in Rome, and opened the door for The there. From the pen of Tertullian (213-218), with its clear definition of an three persons
How completely this Christology won its way in western Christendom Is shown by the treatise on the trinity, written by the roman presbyter Novatian, between 240 and 250 a.d. 
Tertullian, a converted stoic lawyer, was the first to apply the Word “trinity” to the conception or revelation (from human life) of the Triune godhead.  he declared that in his substantia, or substance, God is one. “father, son, and holy spirit”, so Tertullian said, “are Three personae or persons. In “personae” Tertullian seemed to have in Mind the use of that word in roman law where it meant a party in a Legal action.  Tertullian said that the father, the son, and the Holy spirit were three, not in substance but in form: not in power but In appearance, for they are of one substance and essence and one power, Inasmuch as he is one god from whom these and Are reckoned son, and of the holy spirit>. He describes these distinctions of the Godhead as “persons”, of personalities, but forms of manifestation>.  the difference is Not in being or person but in function or activity… “prosopon”, the
Greek word of which the Latin translation is persona. The word means not person but face, and was used of a mask worn by actors in the theater for the part they played.  this doctrine was to remain until the time of Augustine , a century later, when it received its most complete elaboration and most carefully grounded statement — until a real doctrine of the trinity at length came into expression, particularly in the west. 
Tertullian said that the majority of believers are startled at the dispensation of the three in one, on the ground that their very rule of faith withdraws them from the world’s plurality of gods to the one only true God. It was difficult for them to see in Trinitarian conceptions aught else but an assertion of tri-theism (three gods). 
To Tertullian, these personae (persons), or parties, have their place in the “oikonomia” (economy), or administrative activity of god, since god is rational, there was in him reason, the Greek logos. This Reason was god’s own thought. The reason expressed itself in the word,
Word which consists of reason. Yet, there was a time when the reason had not yet expressed itself in word, when, namely, the son was not.  the son was conceived by Tertullian as being subordinate to the Father, and the holy spirit proceeded from the father through the son. 
Tertullian, once a stoic and for a while a montanist, was not an Advocate of logos-Christology, for he admitted that Jesus was god. He Was not a Trinitarian of the later Nicaean school of thought, for he Admitted that there were not three personalities but rather three Manifestations in the godhead. He was not a monarchian because he Taught that the son and the holy spirit emanate from the father by an Eternal process of generation. It seems that he welded the teaching of Logos-Christology and Monarchianism together and remolded them toward a Stepping stone toward Trinitarians. He is regarded by many
Historians as holding of Trinitarians. 
Although he founded the nomenclature of the orthodox doctrine, he knew
As little of an ontological trinity as did the apologists. 
Tertullian employed terms with which he was familiar in the law courts. He was polemical and, like an advocate (lawyer), not always fair to his opponents. He was at times betrayed into inconsistencies. His ideas were sometimes molded by stoic thought. Like the monarchians, whom he attacked, Tertullian believed in the monarchia, or sole government of god. As to the monarchians, so to him, god is one. 
Tertullian bluntly calls the father the whole divine substance, and the son a part of it, illustrating their relation by the figures of The fountain and the stream, the sun and the beam. He would not have two suns he says. The sunbeam, too, in itself considered, may be called sun, but not the sun a beam.