Rom 7:5

“You see then the gain to be got from the former husband! And he does not say when we were in the Law, so in every passage shrinking from giving a handle to heretics; but "when we were in the flesh," that is, in evil deeds, in a carnal life. What he says then is, not that they were in the flesh before, but now they went about without any bodies; but by saying what he does, he neither says that the Law is the cause of sins, nor yet frees it from odium. For it held the rank of a bitter accuser, by making their sins bare: since that, which enjoins more to him who is not minded to obey at all, makes the offence greater. And this is why he does not say, the "motions of sins" which were produced by the Law, but which "were through the Law," without adding any "produced," but simply "through the Law," that is to say, which through the Law were made apparent, were made known. Next that he might not accuse the flesh either; he does not say which the members wrought, but "which did work (or were wrought) in our members," to show that the origin of the mischief was elsewhere, from the thoughts which wrought in us, not from the members which had them working in them. For the soul ranks as a performer, and the fabric of the flesh as a lyre, sounding as the performer obliges it. So the discordant tune is to be ascribed not to the latter, but to the former sooner than to the latter.”

“"In the flesh" means "under the law." Paul calls those laws regarding food, drink, leprosy and so on "flesh." … Paul teaches us that before grace came, while we were still under the law, we suffered ever more serious attacks of sin because, although the law showed us what it was we should be doing, it did not give us any help in doing it.”

“Proving that the law in no way helps us in avoiding fleshly passions, but only reveals them, he says: when we were in the fleshly life and in evil deeds, the sinful passions, exposed by the law and made known through the law, were at work in our members. He did not say that the members produce vices, lest he give occasion for blaming the flesh. For the soul is like a musician, and the members are a lyre. If the musician plays poorly, then the lyre also produces bad sounds. So then, when we were under the law and could not escape the passions, we bore forth death through evil deeds.”

“The second is at for when we were in the flesh. He shows that this fruit was impeded when we were under the slavery of the law, saying, for when we were in the flesh, i.e., subject to the concupiscences of the flesh. But you are not in the flesh, but in the spirit (Rom 8:9). Our passions, however, and affections of sins, which were either explained or rather are occasionally adduced as proof by the law, are accustomed to work in our members, i.e., moved our members: what causes wars and what causes fightings among you? Is it not your passions? (Jas 4:1). And this to bear fruit unto death, i.e., so that they would cause the fruit of death: sin when it is full-grown brings forth death (Jas 1:15).”

“Although he is in the flesh Paul denies that he is "living in the flesh," even though he is in the body. In this passage "living in the flesh" means following something which is forbidden by the law. Therefore "living in the flesh" can be understood in many different ways. For every unbeliever is in the flesh, i.e., is carnal. A Christian living under the law is in the flesh. Anyone who puts his trust in men is in the flesh. Anyone who does not properly understand Christ is in the flesh. If a Christian leads an extravagant life he is in the flesh. Nevertheless, in this passage we should understand "being in the flesh" as meaning that before we believed we were under the power of the flesh. For then we lived under the flesh, i.e., following our carnal desires we were subject to wickedness and sin. For the mind of the flesh is not to understand spiritual things, e.g., that a virgin might conceive without intercourse with a man, that a man may be born again of water and the Spirit, and that a soul delivered from the bondage of the flesh may rise again in it. Anyone who doubts these things is in the flesh.It is clear that whoever does not believe acts under sin and is led by his captivity to indulge in wickedness and to bear fruit worthy of the second death. When such a person sins, death makes a profit. This discussion concerns the Jews and all those who say they are Christians yet still want to live under the law. Its purpose is to teach them that they are carnal so that they will abandon the law. Nevertheless, Paul says that the sins which rule over those who commit them in the flesh are revealed by the law; they are not caused by the law. For the law is the yardstick of sin, not its cause, and it makes sinners guilty.”