Paul probably was as well on his way to sinless perfection as any person ever was, or could be, when he wrote those verses. He could have written in the third person in which it would have read, as follows:
21 I find then the principle that evil is present in them, those who want to do good. 22 For they joyfully concur with the law of God in their inner man, 23 but I see a different law in the members of their body, waging war against the law of their mind and making them prisoners of the law of sin which is in their members. 24 Wretched men that they are! Who will set them free from the body of this death? 25 Thanks be to God through Jesus Christ our Lord! So then, on the one hand they themselves with their minds are serving the law of God, but on the other, with their flesh the law of sin.
Or he could have written in the second person which would have read, as follows:
21 I find then the principle that evil is present in you, who want to do good. 22 For you joyfully concur with the law of God in your inner man, 23 but I see a different law in the members of your body, waging war against the law of your mind and making you prisoners of the law of sin which is in your members. 24 Wretched men that you are! Who will set you free from the body of this death? 25 Thanks be to God through Jesus Christ our Lord! So then, on the one hand you yourselves with your minds are serving the law of God, but on the other, with your flesh the law of sin.
Or he could have even written in the first person plural which would have read, as follows:
21 I find then the principle that evil is present in us, who want to do good. 22 For we joyfully concur with the law of God in our inner man, 23 but I see a different law in the members of our bodies, waging war against the law of our minds and making us prisoners of the law of sin which is in our members. 24 Wretched men that we are! Who will set us free from the body of this death? 25 Thanks be to God through Jesus Christ our Lord! So then, on the one hand we ourselves with our minds are serving the law of God, but on the other, with our flesh the law of sin.
However, he chose to use the first person singular. Many seem to think that he used it merely as a rhetorical method when, in reality, he was so sanctified that it really did not reflect his actual relationship in Christ and that what he was merely doing was providing a helpful device for some who might be struggling with sin. That is rather peculiar given the fact that this same Paul sternly rebuked sin both in Romans and in his other letters.
It makes much more sense to me to take it at face value in its context that Paul really and actually meant what he wrote. After a lifetime of intimate and daily fellowship with God he remained a vile sinner whose only hope was the justification offered through faith alone in Jesus Christ alone.