The following are excerpts from book II (dealing with Christology) from Robert Bellarmine, Controversies of the Christian Faith (trans. Kenneth Baker; Keep The Faith, 2016).
Use of Psa 102:25-26 in Heb 1 applied to Christ
The fourth and fifth places are in Ps. 97:7: All his angels adore him; and Ps. 102:25-26: Of old thou didst lay the foundations of the earth, and the heavens are the work of thy hands. They will perish, but thou dost endure, etc. Paul applies both these places to Christ in Hebrews 1, where he proves that He is greater than the angels, because according to Ps. 97:7 the angels are commanded to adore Christ, and according to Ps. 102:25 Christ is called the creator of heaven and earth, which in no way applies to angels . . .Francis David in the Disputations of the third day; they say that the words, of old, Lord, thou didst lay the foundations of the world, should be understood to be about the Father only, and also on Heb. 1 because Paul wanted to show that Christ is the Son of the true God, and therefore he made an apostrophe to the Father, saying: And you, O Lord, etc. And they prove this, first, because otherwise Paul would be in conflict with the articles of the Apostles’ Creed, where the Father alone is said to be the creator of heaven and earth . .. the solution [proposed by Socinians] is a pure corruption of Scripture. For, Paul is not making an apostrophe to the Father, but he cites various places about Christ, and among others that place, which is obvious from the conjunction “and”: Of the angels he says: Who makes his angels winds, and his servants lame of fire. But of the Son he says, Thy throne, O God, is forever and ever . ..and thou, Lord, didst found the earth in the beginning . . . [I]t is clear from Heb. 1:10 . . . is not to be understood ministerially I prove from the fact that David says the same thing about the God of Israel, whom the adversaries say is the Father, and compares Christ with the angels, and says there is this difference—that the angels are servants. Christ is not a servant; for he says this: But to what angel has he ever said, sit at my might hand, till I make thy enemies a stool for my feet? Are they not all ministering spirits sent forth to serve? (pp. 293, 296, 297; 334; comment in square bracket added for clarification)
Bellarmine on Titus 2:13
[N]ames joined together with one article cannot be referred to two persons. Tit. 2:13: Awaiting our blessed hope, the appearing of the glory of our great God and Savior Jesus Christ.
The Transylvanians following Erasmus refer that “great God” to the Father. But here also one article joined to two names cannot signify two persons: του μεγαλου θεου και σωτηρος. Therefore Chrysostom, Jerome, and others apply it to the Son alone, since they saw that the Greek sentence does not allow for another meaning. Moreover, we are not waiting for the Father to come, but the Son. Paul, however, says that we are waiting for the coming of the glory, that is, the glorious coming (for this is the Hebrew expression of the great God; therefore the Son is the great God. Finally, in Isa. 9:6: For to us a child is born, etc . . . and his name will be called Wonderful Counselor, Mighty God, Everlasting Father; Christ therefore is the Father of all of us. Hence in John 14:18 we have: I will not leave you orphans. And in John 13:33 he calls the Apostles little children. Therefore since all the names of the true God are attributed to Christ, Christ is absolutely the true God. (p. 326)
On the use of the term “Person”
On the word “Person,” the opinion of Valla in book 6, chapter 34 is expressed brilliantly; he says that “person” signifies a quality. For, we say that someone acts like a king, etc., and he adds: if the word “person” is taken for the substance, then there is not in God a person greater than in a brute animal. And finally he says: what the theologians put in God as persons—they are three qualities.
But Valla acts badly in the person of a theologian; for, in God there is a person, but in him there is no quality; or if it pleases to call in God by the name of quality, the thing that are signified by way of quality, then there are not three, but infinite divine persons will have to be named, or only one will be established. If indeed those things which in some way can be said to be qualities in God are distinguished not in reality, but only logically on this account, if the personal properties in God are qualities, there will be one divine person actually, but several logically. If that is what Valla thinks, then he is taking the person of Sabellius in an outstanding manner.
Therefore, although we know that the word “person” is often used for a quality, or for the mask of actors, nevertheless we also know that it is used for the first substance by the Scriptures and by the Fathers. For, in the Scriptures we read passim that God is not the respecter of persons, as in Acts 10:27 and Rom. 1:27 and elsewhere; in these places the word “person” signifies the human hypostasis. For, as Augustine explains in book 2, chapter 7 to Boniface, then there is an acceptance of persons in the distribution of rewards, when the one who distributes does not respect the merits of men, but the men themselves, that is, he gives more to one than to another, not because the one merits more, but because he loves the person more. Moreover, Tertullian calls the Father, the Son and the Holy Spirit three persons in his book against Praxeas, Hilary in the book of the Synods, Jerome in his letters to Damasus, Augustine in book 5 and 7 on the Trinity and among the Greeks Nazianzen in his Oration in praise of Athanasius, and elsewhere he often uses προσωπα. (p.388)
Functionally, many Protestants are Nestorian in their Christology
Luther and Calvin favor this heresy not covertly, at least in their way of speaking. For, Luther in his sermon on the Nativity of the Lord said: Some ignorant people make Christ the man omnipotent. But the same Luther often taught the opposite, so that he seems to have been more a Eutychian than a Nestorian. Beza also saw this and made note of it; for, at the end of his book against the thesis of Jacob Andreas, he quotes the sentence of Luther, and then adds that the sins of Germany and the whole world brought it about that Luther did not persevere in that confession.
But Calvin, in book 1 of his Institutes in chapter 13 § 9, when debating about Christ as he is a certain divine person, says this: I have not yet attained the person of the mediator and in § 23 he said: I respond that he is the Son of God, because he is the Word begotten from the Father before the world; for there is not yet a word for us about the person of the mediator. And in § 24: For because of this, Christ was manifested in the flesh. He is called the Son of God, not only inasmuch as the eternal word was begotten from the Father before the world, but because he assumed the person and office of mediator. There Calvin always seems to distinguish in Christ two persons, one of the Son of God, the other of the Mediator. And it seems that he cannot be excused, as if by the name of the person of the mediator he understands not a substance but a quality, in the way in which we are accustomed to say that another person assumes the person of a judge or of a lawyer. For, in the same § 6 he said: I call the person subsistence. Therefore, at least he cannot be excused for a vicious equivocation. But in a very clear way Brentius favors this heresy in his book on the Majesty of the man Christ, where he often repeats that the Son of God is in the Son of Mary; and Smidelinus does the same in his theses. (Controversy 2, book 3, chapter 5, p. 472)