“Now we know that what things soever the Law saith, it saith to them who are under the Law, that every mouth may be stopped, and all the world may become guilty before God.”… He does not say the Jew, but the whole of mankind. For the phrase, “that every mouth may be stopped,” is the language of a person hinting at them, although he has not stated it clearly, so as to prevent the language being too harsh. But the words “that all the world may become guilty before God,” are spoken at once both of Jews and of Greeks. Now this is no slight thing with a view to take down their unreasonableness. Since even here they have no advantage over the Gentiles, but are alike given up as far as salvation is concerned. For he would be in strict propriety called a guilty person, who cannot help himself to any excuse, but needeth the assistance of another: and such was the plight of all of us, in that we had lost the things pertaining to salvation.” (Homily VII on Romans)
“He saw us in such great guilt, he did not reject us; was not wroth, turned not away, hated us not, for He was a Master, and could not hate His own creation. But what does he do? As a most excellent physician, He prepareth medicines of great price, and Himself tastes them first. For He Himself first followed after virtue, and thus gave it to us. And He first gave us the washing, like some antidote, and thus we vomited up all our guilt, and all things took their flight at once, and our inflammation ceased, and our fever was quenched, and our sores were dried up. For all the evils which are from covetousness, and anger, and all the rest, were dissipated by the Spirit. Our eyes were opened, our ears were opened, our tongue spake holy words: our soul received strength, our body received such beauty and bloom, as it is like that he who is born a son of God should have from the grace of the Spirit; such glory as it is like that the new-born son of a king should have, nurtured in purple.” (Homily XI on Philippians)
In a related note, here are some more proof-texts on ancestral sin from other saints.
St. Cyril of Alexandria said, “Since [Adam] produced children after falling into this state, we, his descendants, are corruptible as the issue of a corruptible source. It is in this sense that we are heirs of Adam’s curse. Not that we are punished for having disobeyed God’s commandment along with him, but that he became mortal and the curse of mortality was transmitted to his seed after him, offspring born of a mortal source . . . So corruption and death are the universal inheritance of Adam’s transgression…Human nature became sick with sin. Because of the disobedience of one (that is, of Adam), the many became sinners; not because they transgressed together with Adam (for they were not there) but because they are of his nature, which entered under the dominion of sin . . . Human nature became ill and subject to corruption through the transgression of Adam, thus penetrating man’s very passions.”
St. Gennadius Scholarius, Patriarch of Constantinople, writes: “Everyone
in the following of Adam has died, because they have all inherited their nature from
him. But some have died because they themselves have sinned, while others have
died only because of Adam’s condemnation – for example, children”.
“Human nature is sinful from its very conception. God did not create man sinful, but pure and holy. But since the first-created Adam lost this garment of sanctity, not from any other sin than pride alone, and became corruptible and mortal, all people also who came from the seed of Adam are participants of the ancestral sin from their very conception and birth. He who has been born in this way, even though he has not yet performed any sin, is already sinful through this ancestral sin.”
– St.Symeon the New-Theologian
“All men from the first to the last are made from the same piece of clay, therefore they all, from the first to the last, form one body and one life. Each is responsible for all, and each is influencing all. If one link of this body sins, the whole body must suffer. If Adam sinned, you and I must suffer for it…”
– St Nikolai Velimirovich
“If the conception of God had been from seed, He would not have been a new man, nor the Author of new life which will never grow old. If He were from the old stock and HAD INHERITED ITS SIN, He would not have been able to bear within Himself the fullness of the incorruptible Godhead or to make His Flesh an inexhaustible Source of sanctification, able to wash away even the defilement of our First Parents by its abundant power, and sufficient to sanctify all who came after them” -St Gregory Palamas
“If anyone asserts that Adam’s transgression injured him alone and not his descendants, or declares that certainly death of the body only, which is the punishment of sin, but not sin also, which is the death of the soul, passed through one man into the whole human race, he will do an injustice to God, contradicting the Apostle who says: ‘As through one man sin entered into the world, and through sin death, so also death passed into all men, in whom all have sinned’”- Council of Orange (529)
Justin Martyr: “Mankind by Adam fell under death, and the deception of the serpent; we are born sinners…NO GOOD THINGS DWELL IN US.”
Eusebius: “The liberty of our will in choosing things that are good is destroyed.”
Cyprian of Carthage: “If, in the case of the worst sinners and of those who formerly sinned much against God, when afterwards they believe, the REMISSION OF THEIR SINS is granted and no one is held back from Baptism and grace, how much more, then, should an INFANT not be held back, who, having but recently been BORN, has done no sin [committed no personal sin], EXCEPT THAT, BORN OF THE FLESH ACCORDING TO ADAM, HE HAS CONTRACTED THE CONTAGION OF THAT OLD DEATH FROM HIS FIRST BEING BORN. For this very reason does he approach more easily to receive the REMISSION OF SINS: because the SINS FORGIVEN HIM are NOT his OWN but THOSE OF ANOTHER [i.e. inherited from Adam]”
Athanasius:”Adam, the first man, altered his course, and through sin death came into the world….When Adam transgressed, SIN reached out TO ALL MEN.”
Ambrose of Milan: “NO CONCEPTION IS WITHOUT INIQUITY, since there are NO PARENTS WHO HAVE NOT FALLEN. And if there is NO INFANT WHO IS EVEN ONE DAY WITHOUT SIN, much less can the CONCEPTIONS of a mother’s womb be WITHOUT SIN.”