In the letter of Arius to Eusebius of Nicomedia (c318), we have his complaint that his bishop is teaching error, namely that:
"... there was 'always a God, always a Son;' 'as soon as the Father, so soon the Son (existed);' 'with the Father co-exists the Son unbegotten, ever-begotten, begotten without begetting;' 'God neither precedes the Son in aspect or in a moment of time;' 'always a God, always a Son, the Son being from God himself.' "
Whereas:
"... what do we say and think and what have we previously taught and do we presently teach? That the Son is not unbegotten, nor a part of an unbegotten entity in any way, nor from anything in existence, but that he (the Son) is subsisting in will and intention before time and before the ages, fully God, the only-begotten, unchangeable." (emphasis mine)
"... Before he was begotten, or created, or defined, or established, he did not exist. For he was not unbegotten. But we are persecuted because we have said the Son has a beginning but God has no beginning. We are persecuted because of that and for saying he came from non-being. But we said this since he is not a portion of God nor of anything in existence. That is why we are persecuted; you know the rest."
What was contended then, was that "there was a time when He was not" and this became something of a mantra for the Arians.
Eusebius replied, and we possess this fragment:
"Since you think properly, pray that everyone will think that way. For it is clear to all that the thing which is made did not exist before it came into being; but rather what came into being has a beginning to its existence."
Meanwhile we have a fragment of a letter from another Eusebius, this time of Caesarea to Euphration of Balanea:
"For we do not say that the Son is coexisting with the Father, but instead that the Father existed before the Son. For if they coexisted, how could the Father be a father, and the Son be a son? Or how could one indeed be the first, and the other second? And how could one be unbegotten and the other begotten? For the two, if they are equal, likewise exist mutually and are honoured equally, one must conclude that either they are both unbegotten or both begotten, as I have said, but it is clear that neither of these is true. For they are neither both unbegotten nor both begotten. For one is indeed the first and best and leads to/precedes the second, both in order and in honour, so that he is the occasion for the second’s existing and for his existing in this particular way."
The contrary view, which in retrospect we know see as Trinitarian, held by a number of Fathers:
"Jesus Christ ... was with the Father before the beginning of time, and in the end was revealed" (Ignatius of Antioch Letter to the Magnesians 6 110AD).
"God begot before all creatures a beginning, who was a certain rational power from himself and whom the Holy Spirit calls ... sometimes the Son ... sometimes Lord and Word." (Justin Martyr, Dialogue with Trypho the Jew 61, c.155AD.)
"(The Gnostics) transfer the generation of the uttered word of men to the eternal Word of God, attributing to him a beginning of utterance and a coming into being ... In what manner, then, would the word of God – indeed, the great God himself, since he is the Word – differ from the word of men?” (Irenaeus Against Heresies 2:13:8 c.185AD).
"God says, 'Let there be light' (Gen. 1:3), this is the perfect nativity of the Word, while he is proceeding from God... Thus, the Father makes him equal to himself, and the Son, by proceeding from him, was made the first-begotten, since he was begotten before all things, and the only-begotten, because he alone was begotten of God, in a manner peculiar to himself, from the womb of his own heart, to which even the Father himself gives witness: 'My heart has poured forth my finest Word' [Ps. 45:1-2]” (Tertullian Against Praxeas 7:1 c.220AD).
"Therefore, this sole and universal God, by reflecting, first brought forth the Word – not a word as in speech, but as a mental word, the reason for everything... The Word was the cause of those things which came into existence, carrying out in himself the will of him by whom he was begotten... Only (God’s) Word is from himself and is therefore also God, becoming the substance of God" (Hippolytus Philosophoumena or Refutation of All Heresies 10:33 c.225AD).
"So also Wisdom, since he proceeds from God, is generated from the very substance of God" (Origen Commentaries on Hebrews c.240).
"There is one God, the Father of the living Word, who is his subsistent wisdom and power and eternal image: perfect begetter of the perfect begotten, Father of the only-begotten Son. There is one Lord, only of the only, God of God, image and likeness of deity, efficient Word, wisdom comprehensive of the constitution of all things, and power formative of the whole creation, true Son of true Father" (Gregory the Wonderworker Declaration of Faith 265AD).
"When we speak of God the Father and God the Son, we do not speak of them as different, nor do we separate them, because the Father cannot exist without the Son, nor can the Son be separated from the Father, since the name of ‘Father’ cannot be given without the Son, nor can the Son be begotten without the Father... They both have one mind, one spirit, one substance" (Lactantius Divine Institutes 4:28–29 307AD).
In the above, we can see the general idea of the Son as eternal, co-existing and consubstantial with the Father, although not yet expressed in firm definitions. These definitions, which become dogmas, are necessary in the face of error. On the whole the Church is loathe to 'define' more than it need.
That God transcends the temporal order is a given. When asked what God was doing before he created the world, Origen argues that 'time' and 'the world' are coeval (On First Principles 3.5.3).
This is a key to Origen's thinking. The Son, the Logos, is the wisdom and power of the Father (1 Corinthians 1.24) and that the world was created through him (Hebrews 1.2). The Logos/Son is He whom "the Lord possessed me at the beginning of his ways" (Proverbs 8:22) and in Wisdom 7.26 is "the brightness of eternal light and the mirror of God's unspotted majesty and the image of His goodness."
To Origen, these texts clearly cannot imply that the Son has a temporal beginning. It is inconceivable that the Father could ever have lacked wisdom, and equally inconceivable to Origen that this wisdom could ever have taken a different form from the one that it now possesses as the second person or hypostasis of the Trinity (Princ. 1.2.2). He is the first theologian to state unequivocally that the “three hypostases” which constitute the Trinity are eternal not only in nature, but in their hypostatic character; there was never a time when wisdom was the latent thought of the Father and had not yet come forth as speech.
If the Father begets not in time – as Arius asserts – it is a mistake to think of a time-before-time, as it is clear that time is dependent first of all on movement, and God is the Motionless Mover, He does not move, in the sense that He is not determined , defined, described or delineated in time. If God begets before time, then God begets in eternity, and God begets eternally.
Origen rejects Arius's "There was a time when He was not" because there is no such time.
Origen’s proposal was simple: If God is the Father, then He is always, eternally, unchangingly, Father. It cannot be that there was a time when the Father was not Father, any more than there could be a time when God was not God. Rather He is the Father and He begets the Son, eternally. God's Son is God's own self-knowledge. The begetting is not a one-time event, it’s a dynamic, a continuum. If God is Creator then it is in His nature to be so.
Arius cannot escape ascribing contingency and finitude to the Father.
