Paul is still under the Law and self-identified in Romans 7:14 as "sold as a slave to sin" in that passage recounting his struggle with sin. So, that's a sinner who wasn't saved yet. He spoke of being delivered once he was in Christ Jesus and no longer walking according to the flesh in Romans 8:1-2. He said, "the law of the Spirit of life in Christ Jesus has made me free from the law of sin and death" (Romans 8:2, comp. John 8:36 and Romans 6:18). That law of sin and death that was still at work in his members in Romans 7:23 was subdued in Christ and he was set free from it because "those who are Christ’s have crucified the flesh with its passions and desires" (Galatians 5:24).
Paul testified as a Christian, "I have been crucified with Christ; it is no longer I who live, but Christ lives in me" (Galatians 2:20). It's not longer a situation of committing sin because of "sin that dwells in me" (Romans 7:17). It was so for the apostle Paul in Christ and should be the same for Christians today because of the foundation laid out in Romans 6.
Romans 6:4-14:
4 Therefore we were buried with Him through baptism into death, that just as Christ was raised from the dead by the glory of the Father, even so we also should walk in newness of life. 5 For if we have been united together in the likeness of His death, certainly we also shall be in the likeness of His resurrection, 6 knowing this, that our old man was crucified with Him, that the body of sin might be done away with, that we should no longer be slaves of sin. 7 For he who has died has been freed from sin. 8 Now if we died with Christ, we believe that we shall also live with Him, 9 knowing that Christ, having been raised from the dead, dies no more. Death no longer has dominion over Him. 10 For the death that He died, He died to sin once for all; but the life that He lives, He lives to God. 11 Likewise you also, reckon yourselves to be dead indeed to sin, but alive to God in Christ Jesus our Lord. 12 Therefore do not let sin reign in your mortal body, that you should obey it in its lusts.
Romans 7 is not the next level from the Romans 6 foundation. The entire chapter (6) actually exemplifies walking under the grace of God, with power received to say 'No' to ungodliness and worldly desires (Titus 2:11-14) and to take this instruction: "Do not present your members as instruments of unrighteousness to sin, but present yourselves to God as being alive from the dead, and your members as instruments of righteousness to God. For sin shall not have dominion over you, for you are not under law but under grace" (Romans 6:13-14). The man who is "carnal, sold under sin" in Romans 7:14 cannot understand that instruction to the Roman believers.
1 Corinthians 2:14
But the natural man does not receive the things of the Spirit of God, for they are foolishness to him; nor can he know them, because they are spiritually discerned.
Paul, the man under the Law and not under grace, and under condemnation as a salve to sin in Romans 7 is not led by God's Spirit in that account. So, it is not a Christian who is struggling in Romans 7, but someone who was not in Christ yet (Romans 8:9b). So, he is a honest man struggling with his sins and seeking a deliverance, which he found in Christ:
Romans 7:24-25
24 O wretched man that I am! Who will deliver me from this body of death*? (comp. Romans 6:6) 25 I thank God—through Jesus Christ our Lord! So then, with the mind I myself serve the law of God, but with the flesh the law of sin.
*sin bring forth death (Romans 6:23, James 1:15)
So, Paul writes again:
Romans 8:1-2
1 There is therefore now no condemnation to those who are in Christ Jesus, who do not walk according to the flesh, but according to the Spirit. 2 For the law of the Spirit of life in Christ Jesus has made me free from the law of sin and death.
At this point the principles of walking according to the Spirit vs walking according to the flesh can apply:
Romans 8:12-14
12 Therefore, brethren, we are debtors—not to the flesh, to live according to the flesh. 13 For if you live according to the flesh you will die; but if by the Spirit you put to death the deeds of the body, you will live. 14 For as many as are led by the Spirit of God, these are sons of God.
"if by the Spirit you put to death the deeds of the body, you will live"
This cannot be done by the man struggling in Romans 7 but it can be done by a believer who has and is led by the Holy Spirit (Romans 8:9 check).
See also:
Freedom From Sin
Crucify the Flesh - video playlist
Old Man Addictions
Works Of Faith Are Not Works Of The Law (video)
Saved From What?
Problem in the Church: Romans 7
Romans 7:14-25 Bible Study
Repentance According to the Bible
The Wretched Man (video)
