Gregory the Theologian-Unity Found Its Rest In Trinity..

Saint Gregory The Theologian

BUT Monarchy is that which we hold in honour. It is, however, a Monarchy that is not limited to one Person, for it is possible for Unity if at variance with itself to come into a condition of plurality; but one which is made of an equality of Nature and a Union of mind and an identity of motion, and a convergence of its elements to unity - a thing which is impossible to the created nature - so that though numerically distinct there is no severance of Essence. Therefore Unity having from all eternity arrived by motion at Duality, found its rest in Trinity. This is what we mean by Father and Son and Holy Ghost. The Father is the Begetter and the Emitter; without passion of course, and without reference to time, and not in a corporeal manner. The Son is the Begotten, and the Holy Ghost the Emission; for I know not how this could be expressed in terms altogether excluding visible things. 

 For we shall not venture to speak of "an overflow of goodness," as one of the Greek Philosophers dared to say, as if it were a bowl overflowing, and this in plain words in his Discourse on the First and Second Causes. Let us not ever look on this Generation as involuntary, like some natural overflow, hard to be retained, and by no means befitting our conception of Deity. Therefore let us confine ourselves within our limits, and speak of the Unbegotten and the Begotten and That which proceeds from the Father, as somewhere God the Word Himself saith. 

When did these come into being? They are above all "When." But, if I am to speak with something more of boldness,-when the Father did. And when did the Father come into being. There never was a time when He was not. And the same thing is true of the Son and the Holy Ghost. Ask me again, and again I will answer you, When was the Son begotten? When the Father was not begotten. And when did the Holy Ghost proceed? When the Son was, not proceeding but, begotten-beyond the sphere of time, and above the grasp of reason; although we cannot set forth that which is above time, if we avoid as we desire any expression which conveys the idea of time. For such expressions as "when" and "before" and "after" and "from the beginning" are not timeless, however much we may force them; unless indeed we were to take the Aeon, that interval which is coextensive with the eternal things, and is not divided or measured by any motion, or by the revolution of the sun, as time is measured.  

How then are They not alike unoriginate, i f They are coeternal? Because They are from Him, though not after Him. For that which is unoriginate is eternal, but that which is eternal is not necessarily unoriginate, so long as it may be referred to the Father as its origin. Therefore in respect of Cause They are not unoriginate; but it is evident that the Cause is not necessarily prior to its effects, for the sun is not prior to its light. And yet They are in some sense unoriginate, in respect of time, even though you would scare simple minds with your quibbles, for the Sources of Time are not subject to time. 

 But they say, The Unbegotten and the Begotten are not the same; and if this is so, neither is the Son the same as the Father. It is clear, without saying so, that this line of argument manifestly excludes either the Son or the Father from the Godhead. For if to be Unbegotten is the Essence of God, to be begotten is not that Essence; if the opposite is the case, the Unbegotten is excluded. What argument can contradict this? Choose then whichever blasphemy you prefer, my good inventor of a new theology, if indeed you are anxious at all costs to embrace a blasphemy. In the next place, in what sense do you assert that the Unbegotten and the Begotten are not the same? If you mean that the Uncreated and the created are not the same, I agree with you; for certainly the Unoriginate and the created are not of the same nature. But if you say that He That begat and That which is begotten are not the same, the statement is inaccurate. For it is in fact a necessary truth that they are the same. For the nature of the relation of Father to Child is this, that the offspring is of the same nature with the parent. 

 Or we may argue thus again. What do you mean by Unbegotten and Begotten, for if you mean the simple fact of being unbegotten or begotten, these are not the same; but if you mean Those to Whom these terms apply, how are They not the same? For example, Wisdom and Unwisdom are not the same in themselves, but yet both are attributes of man, who is the same; and they mark not a difference of essence, but one external to the essence. Are immortality and innocence and immutability also the essence of God? If so God has many essences and not one; or Deity is a compound of these. For He cannot be all these without composition, if they be essences.

Source:  http://www.ellopos.net/elpenor/greek-texts/fathers/gregory-theologian-trinity.asp