The Apostles had no difficulty understanding the nature of God. They had personally interacted with Jesus and he had appeared to them after his resurrection. They knew he had a body before he died and they knew that he had a body after his resurrection. Nowhere does the scriptures suggest that he would ever discard his body. On the contrary, when Christ returns the scriptures say that he will be questioned, "What are these wounds in thine hands?" (Zach. 13:6) Therefore we know that he will still have his body. The doctrine that Jesus and his father were "one" caused some of the confusion. But Christ prayed in that garden that we all should be one, "neither pray I for these alone, but for them also which shall believe on me through their word; That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me." (John 17:20-21) Therefor in whatever way Jesus and his Father are one, we are also to become one. He is not praying that we all lose our identity and become of one substance.
So where did this confusion about the nature of God arise? Greek philosopy was well established at the time of Christ and it conflicted with some of the doctrines taught by Jesus Christ.
"Such was the prestige of the Greek thinkers that their main conclusions were not questioned. Could the Christian teachings be accepted unless they harmonized with the philosophical conclusions? It seemed imperative to reconcile the Christian beliefs with the teachings of the philosophers, at least with such of them as had long been unquestioned and seemed self-evident to the world of that day." (Barker, James L., The Divine Church, Vol 2, p. 24)"Ancient philosophy could not comprehend the creation of the world by God. God's supreme perfection prevented his entering into direct relation with the world; nature is too weak to sustain the immediate action of the divinity. God could not create or act upon his creature except through an intermediary. . . . This intermediary is the Word or Logos, necessarily unequal to the supreme God." (Mourret-Thompson, History of the Catholic Church. vol. 2, p. 13)
"The ideas of beauty, justice, goodness, etc., which for us are abstractions, are for Plato realities. In other words, the good, the beautiful, the just, are abstract ideas, which do not exist apart from the object. But for Plato these abstract ideas are the realities. The objects with which they are associated are perishable, therefore the only reality is the 'idea' or 'form' back of the object.And for Aristotle, "the Supreme Being is immaterial, it can have no impressions, no sensations, nor appetites, nor a will in the sense of desire, nor feelings in the sense of passions: all these things depend on matter." (Weber, History of Philosophy, p. 116)
For Plato, the Supreme Being is absolute goodness and, since matter, for him, is evil and a hindrance to the perfect expression of the 'idea,' God is immaterial" (Barker, James L., The Divine Church, Vol 2, p. 25)
"Very little of 'orthodox' Christian doctrine of today can be traced farther back than the middle of the third century. It was 'developed and made more precise' (Lortz-Kaiser, History of the Church, p. 93) by the Greek method of philosophical reasoning and took form in the councils and the writings of the theologians of the forth and fifth centuries." (Barker, James L., The Divine Church, Vol 2, p. 30)With the conflict between the Greek philosophers who contended for one immaterial God and the Christians who spoke of God the Father and Jesus as being divine, the following questions were being asked:
Originally the term "trinity" did not imply a single God but it was meant to imply the 3 distinct persons of the Godhead.
The Father and Son were only manifestations of one God. Jesus only appeared to be human. The Father was God and Jesus was also divine and numerically distinct. Jesus was not really the Son of God, but his Son by adoption.
"The Church from the time of the apostles considered three "Persons" divine. Towards the end of the second century, Theophilus includes them in a new name, Trinity of Triad. About 200, the Father and the Son are called God, and the Montanists apply the term also to the Holy Ghost." (Barker, James L., The Divine Church, Vol 2, p.34)
Around 320 AD Arius begin to have a strong following for his concept of the Trinity. "For Arius, the second Person of the Trinity did not exist from all eternity, the Son of God was merely the first born of created men." (Mourret-Thompson, History of the Catholic Church, vol 2. p. 11)
This caused a split within the church. Bishop Alexander of Alexandria and his deacon Athanasius were opposed to these views of Arius. "The situation became grave. On one principal point the high clergy of Alexandria were divided; some with Alexander taught the absolute divinity of Christ; others with Arius, recognized only a relative and secondary divinity." (Duchesne, Ancient History of the Church, p. 131)
The pagan public even became interested in the conflict and "The quarrels of Arius and of Alexander echoed even in the theatres." (Duchesne, Histoire ancienne de l'Eglise, vol. 2, p. 138)
Toward 312 AD, when bishop Alexander of Alexandria hear Arius teach that the Son was not co-eternal with the Father, and subordinate to the Father, he forbade him to preach the doctrine. But Arius ignored the bishop. "To put an end to the discussion, Alexander convoked about a hundred bishops from Egypt and Lybia to council in Alexandria, 321. The council condemned the teachings of Arius as heretical, and excommunicated him and his followers. He was obliged to give up his church." (James L. Barker, The Divine Church, vol. 2, p. 38)
At this time Arius left Alexandria for Palestine. He was well received by Eusebius of Caesaria who agreed with his ideas. Eusebius of Nicomedia, the other Eusebius, also agreed with Arius and sought to influence others by writing many letters. Alexander became alarmed at this and also sent letters to various bishops. "My intention was to say nothing about it, . . . But as Eusebius, bishop of Nicomedia, believes himself entrusted with all ecclesiastical matters since having abandoned Beryta he had coveted and occupied the church of Nicomedia without anyone daring to protest; as this Eusebius has made himself the patron of apostates and has undertaken to write letters in his (Arius') support and to attract to the heresy, which attacks Christ, men only slightly acquainted with the question, it appeared urgent for me, who am not ignorant of that which is written in the Law, to keep silence no longer, and to warn all of you, in order that you may be acquainted with both those who have become apostates and with their pernicious expressions of heresy, in order that, if Eusebius writes to you, you may pay no attention to him." (Migne, P. G. t. XVIII, c. 572, cited by Jacquin, Histoire de l'Eglise, vol 1, p. 310) Arius returned to Egypt and the quarrel continued. He composed a work of prose and verse, "The Banquet" in his defense, but only fragments remain.
It is interesting to note here how they tried to resolve the conflict. Apparently there was not a recognized central authority to which the problem could be referred. In the New Testament when a problem arose about observance of the Mosaic Law, it was decided that Paul and Barnabus and some others should go up to Jerusalem to the apostles and the elders. And there they reached a decision which "seemed good to the Holy Ghost, and to us"(Acts 15:1-29)
Such was the condition of the church when Constantine, by his victory over Licinius (324), became master of the Empire, of the Orient as well as of the West. He sought for a method to unify the Empire. "It appeared to him that unity of religion was necessary in order to assure political unity, and that only Christianity was (sufficiently) strong for that because it was the religion of the future." (Boulenger de la Fuente, Historia de la Iglesia, p. 127)
Constantine sent his religious advisor, Hosius, bishop of Cordova, with a letter to Alexander and Arius for them to put aside their dispute. When this effort failed he decided to call a general (ecumenical) council of the church. By the way "ecumenical" is precisely equivalent to imperial; for the technical meaning of e oikoumene (literally, "the inhabited world") was the Roman Empire, as in Luke 2:1 (Smith, Student's Ecclesiastical History, vol 1. p. 254 note).
Considering the Catholic church's claim that the authority for the leadership of the church went from Peter to the Bishop of Rome, the following quote is interesting.
"Most Catholic writers, looking back upon this event (the Council of Nicea), have felt positive that no such assembly could have taken place without the instigation or cooperation of Sylvester (bishop of Rome). Yet all such contemporary evidence as we have concurs in making Constantine alone the author and promoter of the huge enterprise, even as he had been of the Council of Arles. Eusebius gives him the sole credit, as do the letters issued by the Council itself, and he himself, both then and afterwards, spoke of it as the council which he had summoned." (Shotwell and Loomis, The See of Peter, p. 470)
So here we have Constantine who is not a Christian organizing councils and as we shall see, deciding the outcome.
"The opinions (of the members of the Council) followed three directions: The Egyptians and the Occidentals defended the orthodox doctrine (Athanasian) -- Athanasius was the spokesman for Bishop Alexander of Alexandria; the majority of the Orientals (the moderate group) held for the divinity of Christ, but hesitated to recognize his perfect equality with the Father; about twenty adherents of Arius declared the Verb (Jesus) a simple creature." (Albers-Hedde, Manuel d'Histoire Ecclesitique, vol. 1, p. 153)
For Arius the Father and Son were distinct personages and the Son was subordinate to the Father. The Arians used the following scriptures:
After a couple suggestions by Eusebius of Nicodemous, Eusebius of Caesarea then proposed the baptismal formula in use in his own church.
"We believe in One God, Father, all-Sovereign, Creator of all things whatsoever, both visible and invisible; and in one Lord Jesus Christ, the word of God, God of God, Light of Light, Life of Life, only-begotten Son, the First-born of all creation, begotten of God the Father before all the ages, by whom also all things came into being, who became flesh for our salvation, and lived among men, and suffered, and rose again the third day, and ascended to the Father, and will come again in glory to judge the living and the dead. We believe also in one Holy Ghost. (We believe) that each of these is and subsists: the Father truly as Father, the Son truly as Son, the Holy Ghost truly as Holy Ghost; as our Lord also says when he sends his disciples to preach: Go and make all nations disciples, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost."The formula decided upon was the famous Nicene creed: "We believe in one God, the Father Almighty, Maker of all things, both visible and invisible: and in one Jesus Christ, the Son (Word) of God, begotten of the Father, only-begotten, that is of the essence (substance) of the Father. God from God, Light from Light, (Life from Life), very God from very God, begotten not made, of one essence (substance) with the Father, (omoousion to Patri) through whom all things came to be, both things in heaven and things on earth; Who for the sake of us men and for our salvation came down, and was made flesh, and became man, suffered, and rose on the third day, ascended into the heavens (to the Father), is coming to judge living and dead; and in one Holy Ghost." (Bartlett and Carlyle, Christianity in History, p. 265)
The Athanasians were objected to the inference that there was a lack of union of the Son with the Father--"each of these is and subsists." They also refused to accept the expression "the first-born of all creation" [which I find interesting since that is a direct quote of Col. 1:15] and "begotten of the Father before all the ages," since they claim that the Son was co-eternal with the Father.
To prevent false interpretation by the Arians, it was suggested that Jesus be declared to be of the essence (eks ousis) of the Father. Athanasius, it appears, would have been content with this statement, but someone, thought to have been Hosius, proposed the term omoousios, composed of two words, of which one meant the same and the other substance. (James L. Barker, The Divine Church, vol. 2, p. 52)
"This creed of Eusebius was however accepted as the basis of the new symbol, but in an amended form. There was only one way of making Arianism impossible, and that was use a word, which was not only unscriptural, but which was in bad repute as having been used by the heretics Valentinus and Paul of Samosata. [and condemned by the Third Council of Antioch] The Son must be declared to be of one substance or essence (omoousios) with the Father, in order to exclude Arius from the Church. . . . The (h)omoousion left no room for Arianism. If our Lord was declared to be of one substance with the Father, the whole theory of Arius, that He was of a lower nature, and capable of change and even sin, entirely fell to the ground." (Foakes Jackson, History of the Christian Church to A.D. 461, pp. 312, 313)
It turns out that this compromise position was imposed by Constantine. "At the beginning of the council, the party of moderate Arian views, of which Eusebius of Nicomedia was the most influential member, was in the majority, and '(h)omoousios' (one substance) had some difficulty in securing acceptance; it was imposed rather than accepted. Hosius supported it energetically; the same was true of the bishops of Alexandria and Antioch. The Emperor made it known that he desired the use of the word. This was, for many, a capital argument." (Duchesne, Histoire ancienne de l'Eglise, vol. II, pp. 154, 155)
When they placed before the Emperor the formula of the synod, he regarded it as inspired by God, as revealed by the Holy Spirit speaking through the saints, and threatened to exile anyone who would not sign. We have seen the effect of these threats. The Emperor carried them out without delay, and exiled Arius to Illyria, the two bishops Secundus and Theonas, who had refused to sign, and the priests who were attached to them. He commanded at the same time to deliver to the flames the books of Arius and of his friends, and threatened with the penalty of death those who would conceal them . . . Later Eusebius of Nicomedia and Theognis of Nicea were also deposed and banished, because, while admitting the symbol, they did not recognize the deposition of Arius and had admitted the Arians among them. At the same time the churches of Nicea and Nicomedia were invited by the Emperor to elect orthodox bishops in the place of the bishops who had been sent into exile. (Hefele-Leclercq, Histoire des Conciles, tome I, 1 re partie, p. 449-450)After seeing this type of information, some are inclined to try and show that this concept of God was believed by the early Church Fathers.
The historical exposition of J. Kuhn . . . as free as it is learned, frightened the Anglican Bullus, who thought the faith of the high church had been attacked and who sought with great expense of erudition to demonstrate that which is not capable of demonstration: namely, that before the Council of Nicea all the Fathers had clearly and exactly professed the doctrine of Nicea (Hefele-Leclercq, Histoire des Conciles, tome I, 1 re partie, p. 337-338)And so the doctrine of the Trinity was started. It was absent from the scriptures but is now accepted as the "orthodox" doctrine of the Christian church. There was no church leadership, apostles or prophets that decided the issue. Instead it was a pagan ruler that organized and declared his support for this new doctrine. It was his support that shifted the foundation doctrine of Christianity and established it by the force of his power as the basis of faith in the newly adopted religion of the realm.