“The Son can do nothing of Himself, but what He seeth the Father do” (John 5:19).
“All things that the Father hath are the Son’s” (John 16:15), and on the other hand, all that belongs to the Son is the Father’s.
Nothing then is peculiar, because all things are in common. For Their Being itself is common and equal, even though the Son receive it from the Father.
It is in respect of this that it is said “I live by the Father” (John 6:57); not as though His Life and Being were kept together by the Father, but because He has His Being from Him beyond all time, and beyond all cause.
But how does He see the Father doing, and do likewise?
Is it like those who copy pictures and letters, because they cannot attain the truth unless by looking at the original, and being led by the hand by it?
But how shall Wisdom stand in need of a teacher, or be incapable of acting unless taught?
And in what sense does the Father “do” in the present or in the past? Did He make another world before this one, or is He going to make a world to come? And did the Son look at that and make this? Or will He look at the other, and make one like it?
[…] He cleanses lepers, and delivers men from evil spirits, and diseases, and quickens the dead, and walks upon the sea, and does all His other works. But in what case, or when did the Father do these acts before Him?
Is it not clear that the Father impressed the ideas of these same actions, and the Word brings them to pass, yet not in slavish or unskilful fashion, but with full knowledge and in a masterly way, or, to speak more properly, like the Father?
For in this sense I understand the words that whatsoever is done by the Father, these things doeth the Son likewise – not, that is, because of the likeness of the things done, but in respect of the authority.
This might well also be the meaning of the passage which says that the Father worketh hitherto and the Son also (John 5:17); and not only so but it refers also to the government and preservation of the things which He has made, as is shown by the passage which says that “He maketh His angels spirits” (Psalm 103. 4-5, LXX) and that “the earth is founded upon its steadfastness” (though once for all these things were fixed and made) and that the thunder is made firm and the wind created (cf. Amos 4:13).
Of all these things the Word was given once, but the action is continuous even now.
Gregory Nazianzen (c.330-390): Oration 30, 11 (slightly adapted).