Texts Explained; Ninthly, John 10:30; 17:11, etc. Arianexplanation, that the Son is one with the Father in will and judgment; but so are all good men, nay things inanimate; contrast of the Son. Oneness between Them is in nature, because oneness in operation. Angels not objects of prayer, because they do not work together with God, but the Son; texts quoted. Seeing an Angel, is not seeing God. Ariansin fact hold two Gods, and tend to Gentile polytheism. Arianexplanation that the Father and Son are one as we are one with Christ, is put aside by the Regula Fidei, and shown invalid by the usage of Scripture in illustrations; the true force of the comparison; force of the terms used. Force of 'in us;' force of 'as;' confirmed by St. John. In what sense we are 'in God' and His 'sons.'
13 Therefore it was none other than God Himself that David too besought concerning his deliverance, 'When I was in trouble, I called upon the Lord, and He heard me; deliver my soul, O Lord, from lying lips and from a deceitful tongue. ' To Him also giving thanks he spoke the words of the Song in the seventeenth Psalm, in the day in which the Lord delivered him from the hand of all his enemies and from the hand of Saul, saying, 'I will love You, O Lord my strength; the Lord is my strong rock and my defence and deliverer. ' And Paul, after enduring many persecutions, to none other than God gave thanks, saying, 'Out of them all the Lord delivered me; and He will deliver in Whom we trust. ' And none other than God blessed Abraham and Isaac; and Isaac praying for Jacob, said, 'May God bless you and increase you and multiply you, and you shall be for many companies of nations, and may He give you the blessing of Abraham my father. ' But if it belong to none other than God to bless and to deliver, and none other was the deliverer of Jacob than the Lord Himself and Him that delivered him the Patriarch besought for his grandsons, evidently none other did he join to God in his prayer, than God's Word, whom therefore he called Angel, because it is He alone who reveals the Father. Which the Apostle also did when he said, 'Grace unto you and peace from God our Father and the Lord Jesus Christ. ' For thus the blessing was secure, because of the Son's indivisibility from the Father, and for that the grace given by Them is one and the same. For though the Father gives it, through the Son is the gift; and though the Son be said to vouchsafe it, it is the Father who supplies it through and in the Son; for 'I thank my God,' says the Apostle writing to the Corinthians, 'always on your behalf, for the grace of God which is given you in Christ Jesus.' And this one may see in the instance of light and radiance; for what the light enlightens, that the radiance irradiates; and what the radiance irradiates, from the light is its enlightenment. So also when the Son is beheld, so is the Father, for He is the Father's radiance; and thus the Father and the Son are one.
14. But this is not so with things originate and creatures; for when the Father works, it is not that any Angel works, or any other creature; for none of these is an efficient cause, but they are of things which come to be; and moreover being separate and divided from the only God, and other in nature, and being works, they can neither work what God works, nor, as I said before, when God gives grace, can they give grace with Him. Nor, on seeing an Angel would a man say that he had seen the Father; for Angels, as it is written, are 'ministering spirits sent forth to minister,' and are heralds of gifts given by Him through the Word to those who receive them. And the Angel on his appearance, himself confesses that he has been sent by his Lord; as Gabriel confessed in the case of Zacharias, and also in the case of Mary, bearer of God. And he who beholds a vision of Angels, knows that he has seen the Angel and not God. For Zacharias saw an Angel; and Isaiah saw the Lord. Manoah, the father of Samson, saw an Angel; but Moses beheld God. Gideon saw an Angel, but to Abraham appeared God. And neither he who saw God, beheld an Angel, nor he who saw an Angel, considered that he saw God; for greatly, or rather wholly, do things by nature originate differ from God the Creator. But if at any time, when the Angel was seen, he who saw it heard God's voice, as took place at the bush; for 'the Angel of the Lord was seen in a flame of fire out of the bush, and the Lord called Moses out of the bush, saying, I am the God of your father, the God of Abraham and the God of Isaac and the God of Jacob,' yet was not the Angel the God of Abraham, but in the Angel God spoke. And what was seen was an Angel; but God spoke in him. For as He spoke to Moses in the pillar of a cloud in the tabernacle, so also God appears and speaks in Angels. So again to the son of Nun He spoke by an Angel. But what God speaks, it is very plain He speaks through the Word, and not through another. And the Word, as being not separate from the Father, nor unlike and foreign to the Father's Essence, what He works, those are the Father's works, and His framing of all things is one with His; and what the Son gives, that is the Father's gift. And he who has seen the Son, knows that, in seeing Him, he has seen, not Angel, nor one merely greater than Angels, nor in short any creature, but the Father Himself. And he who hears the Word, knows that he hears the Father; as he who is irradiated by the radiance, knows that he is enlightened by the sun.
15. For divine Scripture wishing us thus to understand the matter, has given such illustrations, as we have said above, from which we are able both to press the traitorous Jews, and to refute the allegation of Gentiles who maintain and think, on account of the Trinity, that we profess many gods. For, as the illustration shows, we do not introduce three Origins or three Fathers, as the followers of Marcion and Manichæus; since we have not suggested the image of three suns, but sun and radiance. And one is the light from the sun in the radiance; and so we know of but one origin; and the All-framing Word we profess to have no other manner of godhead, than that of the Only God, because He is born from Him. Rather then will the Ario-maniacs with reason incur the charge of polytheism or else of atheism, because they idly talk of the Son as external and a creature, and again the Spirit as from nothing. For either they will say that the Word is not God; or saying that He is God, because it is so written, but not proper to the Father's Essence, they will introduce many because of their difference of kind (unless forsooth they shall dare to say that by participation only, He, as all things else, is called God; though, if this be their sentiment, their irreligion is the same, since they consider the Word as one among all things). But let this never even come into our mind. For there is but one form of Godhead, which is also in the Word; and one God, the Father, existing by Himself according as He is above all, and appearing in the Son according as He pervades all things, and in the Spirit according as in Him He acts in all things through the Word. For thus we confess God to be one through the Triad, and we say that it is much more religious than the godhead of the heretics with its many kinds, and many parts, to entertain a belief of the One Godhead in a Triad.
Source: Four Discourses Against the Arians (New Advent)