De Sententia Dionysii

²² The relation of the Son to the Father is essential, according to Dionysius.

For let not any Arian suppose that he says even anything of the following kind: The Son coexists with the Father, so that while the names are correlated, the things are widely removed; and whereas the Son did not always coexist with the Father, since the Son came into being, God received from that fact the additional name of Father, and His coexistence with Him dates from that time as happens in the case of men. On the contrary, let him observe and bear in mind what we have said before, and he will see that the faith of Dionysius is correct. For in saying, 'For there was no time when God was not Father,' and again, 'God at any rate is light eternal without beginning nor ever to end, accordingly the brightness is eternally before Him and coexists with Him, without beginning and ever-begotten, shining in His presence,' he should make it impossible for any one to entertain any such suspicion against him. Moreover the examples of the well and the river, and the root and the branch, and the breath and the vapour, put to shame the adversaries of Christ when they reiterate the contrary against him.