Actually Paul said that he no longer sins,that sin sins all by itself and has simply become an unwanted occupant of Paul's earthly tent.
Romans 7:17 Now then it is no more I that do it, but sin that dwelleth in me.
The Gentiles are under the covenant of the rainbow or Noah's covenant.
There is no threat of any kind of torture for disobeying it but there was also no promise of life.
Since whatever is not of faith is sin then it stands to reason that faith is the mark.
I left out a law in the my previous post, the Law of Liberty (James 2:12)
I get a different view of Paul here, he isn't accountable for his sins, but he realizes that he still does sin sometimes. There is a big difference between saying "it is not I that sins" and "I have no sin at all".
Php 3:12 Not that I have already obtained it or have already become perfect, but I press on so that I may lay hold of that for which also I was laid hold of by Christ Jesus.
Php 3:13 Brethren, I do not regard myself as having laid hold of it yet; but one thing I do: forgetting what lies behind and reaching forward to what lies ahead,
Rom 7:24 Wretched man that I am! Who will set me free from the body of this death?
Rom 7:25 Thanks be to God through Jesus Christ our Lord! So then, on the one hand I myself with my mind am serving the law of God, but on the other, with my flesh the law of sin.
If no faith is the only sin, then we are back to adultery, murder, pornography, homosexuality, etc... aren't sin.
Rom 6:12 Therefore do not let sin reign in your mortal body so that you obey its lusts,
Jas 1:14 But each one is tempted when he is carried away and enticed by his own lust.
Jas 1:15 Then when lust has conceived, it gives birth to sin; and when sin is accomplished, it brings forth death.
Jas 1:22 But prove yourselves doers of the word, and not merely hearers who delude themselves.
Jas 2:14 What use is it, my brethren, if someone says he has faith but he has no works? Can that faith save him?
Jas 2:20 But are you willing to recognize, you foolish fellow, that faith without works is useless?
Jas 2:21 Was not Abraham our father justified by works when he offered up Isaac his son on the altar?
Jas 2:22 You see that faith was working with his works, and as a result of the works, faith was perfected;
Jas 2:23 and the Scripture was fulfilled which says, "AND ABRAHAM BELIEVED GOD, AND IT WAS RECKONED TO HIM AS RIGHTEOUSNESS," and he was called the friend of God.
Jas 2:24 You see that a man is justified by works and not by faith alone.
Jas 2:25 In the same way, was not Rahab the harlot also justified by works when she received the messengers and sent them out by another way?
Jas 2:26 For just as the body without the spirit is dead, so also faith without works is dead.
Of course works and good deeds aren't what save us, but if you have no outward fruit, no evidence of change, perhaps you aren't changed.
Eph 4:1 Therefore I, the prisoner of the Lord, implore you to walk in a manner worthy of the calling with which you have been called,
Col 1:10 so that you will walk in a manner worthy of the Lord, to please Him in all respects, bearing fruit in every good work and increasing in the knowledge of God;
1 Thes 2:12 so that you would walk in a manner worthy of the God who calls you into His own kingdom and glory.
1 Thes 5:22 abstain from every form of evil.
1 Thes 5:23 Now may the God of peace Himself sanctify you entirely; and may your spirit and soul and body be preserved complete, without blame at the coming of our Lord Jesus Christ.
Eph 4:26 BE ANGRY, AND yet DO NOT SIN; do not let the sun go down on your anger,
Paul told the Corinthians they had sin in their church, and it wasn't just a sin of unbelief.
1 Cor 5:1 It is actually reported that there is immorality among you, and immorality of such a kind as does not exist even among the Gentiles, that someone has his father's wife.