5 But what shall I say, Brethren? Let us not be angry with them; but pray we for them, that God would give them understanding; for perhaps they were born so. What is, were born so? They receive what they hold from their parents. They prefer their birth to the truth. Let them become what they are not, that they may be able to keep what they are; that is, let them become Catholics, that they may keep their nature as men; that the creation of God in them perish not, let the grace of God be added to them.
For they imagine that by their outrage of the Son they honour the Father. When you say to him, “Thou blaspheme;” he answers, “Why do I blaspheme?” “In that you say that the Son is not what the Father is.” And he answers me, “Yea, it is you who blasphemes.” Why? “Because you would make the Son equal to the Father.” “I do wish to make the Son equal with the Father, but is this to make a stranger equal? The Father rejoices when I equal with Him His Only Son; He rejoices because He is not envious.
And because God is not envious of His Only Son, therefore did He beget Him Such as He is Himself. You do wrong both to the Son, and to the Father Himself, for whose honour you would do outrage to the Son. For in truth for this reason do you say that the Son is not of the Same Substance, lest you should do wrong to His Father. I will soon show you, that you do wrong to both.” “How?” says he. “If I say to any man's son, You are degenerate, you are not like your father; degenerate, you are not what your father is.
The son hears it, and is angry, and says, 'Was I then born degenerate?' The father hears it, and is more angry still. And in his anger what says he? 'Have I then begotten a degenerate son? If I then be one thing, and I have begotten another, I have begotten a monster.' What is it then, that whereas you wish to pay honour to the One by doing outrage to the Other, you do outrage to Both? Thou offendest the Son, but you will not propitiate the Father. When you honour the Father by outraging the Son, you offend both the Son and the Father.
From whom will you fly? To whom will you fly? When the Father is angry with you, do you fly to the Son? What does He say to you? 'To whom do you fly, to Me, whom you have made degenerate?' When the Son is offended, do you run to the Father? He too says to you; 'To whom do you fly, to Me who, you have said, have begotten a degenerate Son.'” Let this suffice for you; hold it fast, commit it to memory, inscribe it in your faith. But that you may understand it, pour out your prayers to God, the Father and the Son, who are One.
Source: Sermons on Selected Lessons of the New Testament (New Advent)