Romans 3:9

"What then do we hold further? For we have charged that Jews and Greeks are all under sin, as it is written: That there is none righteous, none that understands, none that seeks after God. All have turned aside, they have together become unprofitable; there is none that does goodness, there is not so much as one. Their throat is an open sepulchre, with their tongues they dealt deceitfully, the poison of asps is under their lips, whose mouth is full of cursing and bitterness: their feet are swift to shed blood.

Finally, in that passage where he said: “But I was alive without the law once,” he added: “But when the commandment came, sin revived.” In this he shows indeed that in childhood, before one has discernment of good and evil, a person is said to be without law; since even if he sins, because the law is not in him, sin is not imputed to him. But when he has received discernment of good and evil, the law is said to have come to him and to have given him commandments. Now where the force of the commandment is present — that is, a conscience that convicts — sin, which before was dead in him, is said to have revived. From this time on, therefore, if anyone subjects himself to the law of Moses so as to observe it according to the letter, he becomes a Jew outwardly; but if he follows it according to the spirit, he becomes a Jew inwardly. These things are said with respect to what was written: “For we have charged that all, both Jews and Greeks, are under sin.” That is, let “all” be understood as spoken of those who, it is agreed, are taught not to sin either by the natural law or by the written law. For concerning the Gentiles too, who are placed under sin, we understand it in the same way we said above: when they have begun to do naturally the things of the law and to be a law to themselves, then they are convicted by conscience in those things which they are seen to do against the law. For this reason those men also seem to me to have judged rightly who call the law of nature the law of God, and call the law of Moses the written law. For if Paul were speaking of the written law, that is, of the law of Moses, when he says: “But sin is not imputed when there is no law,” it will seem that sin was not reckoned to Cain, nor to those who perished in the flood, nor to those whom fire consumed in Sodom. […]

"What then have we more than they? For we have proved both Jews and Gentiles, that they are all under sin. As it is written, There is none righteous, no, not one." He had accused the Gentiles, he had accused the Jews; it came next in order to mention the righteousness which is by faith. For if the law of nature availed not, and the written Law was of no advantage, but both weighed down those that used them not aright, and made it plain that they were worthy of greater punishment, then after this the salvation which is by grace was necessary. Speak then of it, O Paul, and display it. But as yet he does not venture, as having an eye to the violence of the Jews, and so turns afresh to his accusation of them; and first he brings in as accuser, David speaking of the same things at length, which Isaiah mentioned all in short compass, so furnishing a strong curb for them, so that they might not bound off, nor any of his hearers, while the matters of faith were laid open to them, might after this start away; being beforehand safely held down by the accusations of the prophets. For there are three excesses which the prophet lays down; he says that all of them together did evil, and that they did not do good indifferently with evil, but that they followed after wickedness alone, and followed it also with all earnestness. And next that they should not say, "What then, if these things were said to others?" he goes on:

Paul is saying: "Why go on talking like this? For we have shown by the examples given that all, Jews and Gentiles alike, are guilty and that the law is being pursued in vain." For Paul first showed that the Gentiles are guilty according to …

After showing the Jews' advantage over the gentiles so far as God's blessings are concerned, the Apostle now rejects their vainglory, by which they preferred themselves to gentiles converted to the faith. First, he states his point; second, he proves it, at for we have …