Continuing in Bossuet’s Elevations on the Mysteries, 2,2:
A God, can a God come from him? A God, can he bring into existence a being other than himself? Yes, if this God is son. It is repugnant to God to come from another creator who pulls him from nothing; but it is not repugnant to God to come from another like a father who generates him from his own substance. More than that a son is perfect, if one can speak in this way, a son is more of a son if he is of the same nature and substance as his father; more if he is one with him; and if he can be of the same nature and individual substance, he will be more of a perfect son. But what nature could be so rich, so infinite, so immense for this, if it is not the only infinite and immense, that is to say the only divine nature? It is such which he has revealed to us that God is Father, that God is Son, and that the Father and Son are one God alone: because the Son generated from the substance of his father which does not admit division, and has no parts, which cannot be anything less than God and the same God with his Father. For who speaks of the substance of God, says it all, and says by consequence God entirely. And who comes from God of this kind, that is to say of all his substance, has at the same time the entirety of his eternity, as the Prophet says: His going out is from the beginning, from the days of eternity: because eternity is the substance of God, and whatever comes from God and his substance, necessarily comes with the same eternity, the same life, the same majesty. For if a father transmits to his son all his nobility, how much more does the Eternal Father transmit to his son all his nobility, with all the perfection and the eternity of his being? In this way the Son of God is necessarily co-eternal with his Father: for he cannot have anything new or in time in the womb of God. The changing and passage of time of nature is to always change, this does not approach his august womb; and, the same perfection, the same fulness of being which in excluding nothing, excludes all changeable nature. In God, all is permanent, all is changeless; nothing flows in his being; nothing new comes up; and, what makes up a sole moment, if one can speak of a moment in God, is always. In the beginning the Word was: go back to the origin of the world, the Word was. Go back higher, if you can and place all the years which you like one after another, he was. He is like God the one who is. Saint John said in the Apocalypse (Revelation 1,4) may grace be given to you by he who is none other than he who is, who was and who is to come: it is God. And a little after, it is Jesus Christ of whom saint John speaks: See him who comes in the clouds. (v. 7) And it is him who pronounces these words: I am the alpha and omega, the beginning and the end, says the Lord God, who is and was and is to come. Jesus Christ is thus like his father, he who is and who was: he is the one whose immensity wraps around the beginning and the end of things; and, like Son, being of the same nature and substance of his Father, is he also of the same being, the same duration, and the same eternity.