But what wonder is there, if this can be said in the case of some twofold things widely different from each other? For what are so different as soul and body? Yet we can say the soul was with a man, that is, in a man; although the soul is not the body, and man is both soul and body together. So that what follows in the Scripture, "And the Word was God,"  may be understood thus: The Word, which is not the Father, was God together with the Father. Are we then to say thus, that the Father is the begetter of His own greatness, that is, the begetter of His own power, or the begetter of His own wisdom; and that the Son is greatness, and power, and wisdom; but that the great, omnipotent, and wise God, is both together? How then God of God, Light of Light? For not both together are God of God, but only the Son is of God, that is to say, of the Father; nor are both together Light of Light, but the Son only is of Light, that is, of the Father. Unless, perhaps, it was in order to intimate and inculcate briefly that the Son is co-eternal with the Father, that it is said, God of God, and Light of Light, or anything else of the like kind: as if to say, This which is not the Son without the Father, of this which is not the Father without the Son; that is, this Light which is not Light without the Father, of that Light, viz. the Father, which is not Light without the Son; so that, when it is said, God which is not the Son without the Father, and of God which is not the Father without the Son, it may be perfectly understood that the Begetter did not precede that which He begot. And if this be so, then this alone cannot be said of them, namely, this or that of this or that, which they are not both together. Just as the Word cannot be said to be of the Word, because both are not the Word together, but only the Son; nor image of image, since they are not both together the image; nor Son of Son, since both together are not the Son, according to that which is said, "I and my Father are one."  For "we are one" means, what He is, that am I also; according to essence, not according to relation.
 [The term "God," in the proposition, "the Word was with God," must refer to the Father, not to "the Father and Son together," because the Son could not be said to be "with" himself. St. John says that "the word was God" (theos). The absence of the article with theos denotes the abstract deity, or the divine nature without reference to the persons in it. He also says that "the Word was with God" (ton theon). The presence of the article in this instance denotes one of the divine persons in the essence: namely, the Father, with whom the Word was from eternity, and upon whose "bosom" he was from eternity. (John 1:18).--W.G.T.S.]  John 1:1  John 10:30
 John 1:1
 John 10:30