This is a mixture of truth and error or a half truth.
We can agree on #1
We do not agree on #2 because it is the SAME law written on the Conscience of the Gentile that is EXPANDED in the writings of Moses - both represent the RIGHTEOUSENSS of God.
#4 does not rightly represent Paul's argument. Both are EQUALLY condemned UNDER THE LAW as sinners and NEITHER is justified by the Law of God whether it is written on conscience or on stone/skins.
#5-6 is pure delusion and distortion of Paul's argument. Righteousness is REVEALED in the PERSON and works of Christ which is IMPUTED to sinners through faith. Justification has nothing to do with IMPARTATION of righteousness as that is the work of regeneration manifested in progressive sanctification. There is not one word of IMPARTATION or faith that produces works for justification in this entire passage. That subject is taken up in Romans 6-8 in connection with the indwelling Spirit of God and the regenerate nature.
The correct line of development by Paul is:
1. The Wrath of God is revealed against ungodly men - ch. 1:18-32
2. There are no men better than other men and judgement under the Law will demonstrate it as both jews and Gentiles have violated the law whether it be the Law of Moses or the law of conscience - ch 2;1-16
3. The Jew is not better than the Gentile as he is a hypocrit which invalidates his professed obedience to law and circumcision - ch. 2:17-29
4. The Jew has better revelation and privileges than the Gentiles - chs. 2:30-3:2
5. However, failure in light of revelation and priveleges is not God's fault - ch. 3;3-8
6. Jews and Gentiles are by nature sinners - ch. 3:9-18
7. Hence, the WHOLE WORLD is judged and condemned by the Law of God so that "every mouth" and "no flesh" can be justified by keeping law as that is not the purpose of the law - ch.3:19-20a
8. The Purpose of the Law and the prophets is to reveal sin and the righteosness of God that is now manifested in the Person and works of jesus Christ - ch. 3:20b-22
9. It is this righteousnes manifested in the person and work of Jesus Christ that all men without exception have come short - ch. 3:23
10. It is this righteousenss manifested in the Person and work of Jesus Christ that has propitiated (satisfied the legal demands of God) and is the basis of justiication received "freely by his grace" thorugh faith in Christ. - ch. 3:24-26
11. Because Christ satisfied the righteous demands of God in His own Person by His own works there is no grounds for boasting in justification because justification is by the "law" of faith which "law" excludes both Jews and Gentiles works of the law - ch. 3:27-28
12. This total exclusion of our works makes the ground level between Jews and Gentiles as all works are excluded. - ch. 3:29-30
13. Justification freely by His grace through faith in the satisfaction provided in the Person and works of Jesus Christ fully "establish" the Law as Christ satisfied it completely in His own Person and in His own works which we receive by faith alone. - ch. 3:31
14. Abraham is an example of both a GENTILE and Father of the Jews and his Pre-Torah good works played no part in his justication because justication is IMPUTED by faith not by his good works - Rom. 4:1-3
15. The nature of works = what people do = is opposed to grace and akin to debt and opposed to faith because justification is obtained by imputation without works - ch. 4:4-6
16. The blessed man obtains justification = imputed righteousness and non-imputed righteousness by faith - ch. 4:7-8
17. Therefore:
This blessedness is not obtained in connection with ordinances - vv. 9-11
This blessedness is not obtained in connection with law obedience - vv. 12-15
This blessedness is not obtained in connection with any kind of personal contributions - vv. 16-20
This blessedness is obtain by faith in God's power to obtain God's promises - v. 21
18. This is exactly how justification by faith in the gospel is received - vv 22-25
16.
a Gentile and father of the Jews