>>23586 (OP)
Also in your previous thread https://archive.is/ZEtZy I cited the doctrine of consubstantiality and did not realize I was indirectly quoting St. Athanasius on the subject, from Against the Arians:
>But it is not so, as they think; for not understanding that He is genuine Son from the Father, they belie Him who is such, whom alone it befits to say, 'I in the Father and the Father in Me.' For the Son is in the Father, as it is allowed us to know, because the whole Being of the Son is proper to the Father's essence , as radiance from light, and stream from fountain; so that whoever sees the Son, sees what is proper to the Father, and knows that the Son's Being, because from the Father, is therefore in the Father. For the Father is in the Son, since the Son is what is from the Father and proper to Him, as in the radiance the sun, and in the word the thought, and in the stream the fountain: for whoever thus contemplates the Son, contemplates what is proper to the Father's Essence, and knows that the Father is in the Son. For whereas the Form and Godhead of the Father is the Being of the Son, it follows that the Son is in the Father and the Father in the Son.
>On this account and reasonably, having said before, 'I and the Father are One,' He added, 'I in the Father and the Father in Me, John 10:30 ' by way of showing the identity of Godhead and the unity of Essence. For they are one, not as one thing divided into two parts, and these nothing but one, nor as one thing twice named, so that the Same becomes at one time Father, at another His own Son, for this Sabellius holding was judged an heretic. But They are two, because the Father is Father and is not also Son, and the Son is Son and not also Father ; but the nature is one; (for the offspring is not unlike its parent, for it is his image), and all that is the Father's, is the Son's. Wherefore neither is the Son another God, for He was not procured from without, else were there many, if a godhead be procured foreign from the Father's ; for if the Son be other, as an Offspring, still He is the Same as God; and He and the Father are one in propriety and peculiarity of nature, and in the identity of the one Godhead, as has been said. For the radiance also is light, not second to the sun, nor a different light, nor from participation of it, but a whole and proper offspring of it. And such an offspring is necessarily one light; and no one would say that they are two lights , but sun and radiance two, yet one the light from the sun enlightening in its radiance all things. So also the Godhead of the Son is the Father's; whence also it is indivisible; and thus there is one God and none other but He. 'And so, since they are one, and the Godhead itself one, the same things are said of the Son, which are said of the Father, except His being said to be Father' :— for instance , that He is God, 'And the Word was God John 1:1;' Almighty, 'Thus says He which was and is and is to come, the Almighty Revelation 1:8;' Lord, 'One Lord Jesus Christ 1 Corinthians 8:6;' that He is Light, 'I am the Light John 8:12;' that He wipes out sins, 'that you may know,' He says, 'that the Son of man has power upon earth to forgive sins Luke 5:24;' and so with other attributes. For 'all things,' says the Son Himself, 'whatsoever the Father has, are Mine ;' and again, 'And Mine are Yours.'
>And on hearing the attributes of the Father spoken of a Son, we shall thereby see the Father in the Son; and we shall contemplate the Son in the Father, when what is said of the Son is said of the Father also. And why are the attributes of the Father ascribed to the Son, except that the Son is an Offspring from Him? And why are the Son's attributes proper to the Father, except again because the Son is the proper Offspring of His Essence? And the Son, being the proper Offspring of the Father's Essence, reasonably says that the Father's attributes are His own also; whence suitably and consistently with saying, 'I and the Father are One,' He adds, 'that you may know that I am in the Father and the Father in Me.' Moreover, He has added this again, 'He that has seen Me, has seen the Father ;' and there is one and the same sense in these three passages. For he who in this sense understands that the Son and the Father are one, knows that He is in the Father and the Father in the Son; for the Godhead of the Son is the Father's, and it is in the Son; and whoever enters into this, is convinced that 'He that has seen the Son, has seen the Father.' for in the Son is contemplated the Father's Godhead.
https://www.newadvent.org/fathers/28163.htm