Romans 7:15-19
15 I do not understand what I do. For what I want to do I do not do, but what I hate I do. 16 And if I do what I do not want to do, I agree that the law is good. 17 As it is, it is no longer I myself who do it, but it is sin living in me. 18 For I know that good itself does not dwell in me, that is, in my sinful nature. For I have the desire to do what is good, but I cannot carry it out. 19 For I do not do the good I want to do, but the evil I do not want to do—this I keep on doing.
The context of Paul's struggle is mentioned in verse 3 within Romans 8.
"For
what the law could not do, in that it was weak through the flesh,
God sending his own Son in the likeness of sinful flesh, and for sin,
condemned sin in the flesh:" (Romans 8:3).
Did you catch that?
Paul's mention of his struggle in Romans 7:14-24 is referenced in Romans 8:3 when he says, "What the law could not do, in that it was weak through the flesh, God sending his own Son.... condemned sin in the flesh." Paul discovered first hand what the Law could not do and that it was weak through the flesh in Romans 7:14-24. God sent his own Son and condemned sin the flesh. Which Law existed when Jesus condemned sin in the flesh upon the cross? Was it the Old Covenant Law or the New Covenant Law? Surely it was the Old Law because the commands from Christ's followers were not given yet. Paul says that what he had written should be regarded as the Lord's commandments.
"If any man think himself to be a prophet, or spiritual, let him acknowledge that the things that I write unto you are the commandments of the Lord." (1 Corinthians 14:37).
So there is New Covenant Laws or Commands.
Anyways, let's keep reading.
4
That the righteousness of the law might be fulfilled in us, who walk not after the flesh, but after the Spirit.
5
For they that are after the flesh do mind the things of the flesh; but they that are after the Spirit the things of the Spirit.
6
For to be carnally minded is death; but to be spiritually minded is life and peace.
7 Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be.
8
So then they that are in the flesh cannot please God."
Flesh here is talking about sin. They that are carnal or in the flesh (sin) cannot please God. For they that are after the flesh (carnal) do mind the things of the flesh (sinful things). In any event, verse 4 says that the righteousness of the Law might be fulfilled in us who not after the flesh (sin or ourselves) but after the Spirit. What is the righteousness (righteous aspect or part) of the Law? It is loving one's neighbor as their self (i.e. the Moral Law - See Romans 13:8-10). What this tells us is that there is (a) Is Law still under the New Covenant (b) Jesus condemned sin on the cross which the Old Law could not accomplish. According to Romans 8:3, trying to keep the Old Law alone (without Jesus) made one weak in the flesh. But with Jesus, we can overcome sin.
This is why Romans 13:14 says,
"But
put ye on the Lord Jesus Christ, and make not provision for the flesh, to fulfil the lusts thereof."