Rome Teaches the very opposite of the gospel of Jesus Christ or what Paul identifies as "another gospel."
They fail to discern the vital distinction between faith "in" the propiatitory Person and works of Jesus Christ versus faithfulness to Christ.
Romans 3:23-28 is a decisve and fatal blow to the whole soteriological system of Rome.
23 For all have sinned, and come short of the glory of God;
24 Being justified freely by his grace through the redemption that is in Christ Jesus:
25 Whom God hath set forth to be a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God;
26 To declare, I say, at this time his righteousness: that he might be just, and the justifier of him which believeth in Jesus.
27 Where is boasting then? It is excluded. By what law? of works? Nay: but by the law of faith.
28 Therefore we conclude that a man is justified by faith without the deeds of the law.
Verse 23 is universal in its comprehensive condemnation of "all" NATURAL born humanity and therefore demonstrates there is no cause found in natural born man that provides any grounds for justification before God but only universal condemnation as the standard for justification is "the glory of God" and "all" have come short of that standard of righteousness.
Verse 24 demands that justification is "freely" or without a cause found in sinful man just as verse 23 declares "all" come short of that basis for justification. Moreover "freely" modifes "grace" demonstrating that "grace" cannot have its basis in humanity but rather has its basis "in Christ Jesus."
Verse 25 demonstrates that the basis of grace found "in Christ Jesus" is in regard to the satisfaction provided by God in the person and redemptive work of Jesus Christ alone and that it is faith "in" this provision that justifies those who have "come short of the glory of God." It is "freely" or without any cause found in the believer but in the object embraced by faith. Not faithfulness by the believer to Christ but faith "in" Christ's propiatiatory sacrifice as set forth by God as the OBJECT OF FAITH.
This same provision was set forth from the garden of Eden until the present as the only basis for propitiation/satisfaction and therefore believers in the gospel prior to Calvary were justified by faith in the same provision (Abraham - Rom. 4:1-25; Gal. 3:6-25) as those after Calvary - "for the remission of sins that are past, through the forbearance of God; To declare, I say, at this time his righteousness: that he might be just, and the justifier of him which believeth in Jesus."
"To Him give all the prophets witness that whosoever believeth in his name shall receive remission of sins." - Acts 10:43
"For unto us was the gospel preached, as well as unto them: but the word preached did not profit them, not being mixed with faith in them that heard it." Heb. 4:2
Verse 27 asks the question "where is boasting" as a direct conclusion to the words "freely by grace" in verse 24 and due to the "propitiation" provided by God in verse 25 that is in Christ rather than what we provide for Christ. The propitiation that is embraced by faith rather than what is produced by faithfulness. Rome is utterly ignorant of this distinction. This is the same word translated "glory" in Romans 4:2 where the same question is asked in regard to Abraham's justification and again placed in direct contrast with "works" of the law.
Moreover, this question entertains only two possible contrasting options which both are commonly identified as "LAW"!! "by what law?" Either it is justification by the "law" or principle "of faith" or it is a justification that is characterized by the "law" or principle "of works." - "And if it is of the law [of works]then it is not of faith" - Gal. 3:10,12.
Justification after the priniciple/law "of works" not only includes the Mosaic Law in specific but ANY and EVERY kind of justification "of works" in general. Hence, Paul is not merely condemning justification under Mosaic Law "of works" but ANY kind of justification "of works" because he is condeming the principle/law "of works" because it repudiates the completed propitiatory work of Jesus Christ and denies that HIS WORKS were sufficient and efficient for justification of "the ungodly" (Rom. 4:5) "without works" (Rom. 4:6). Romans 4:1-6 is speaking about Abraham PRIOR TO ANY MOSAIC LAW OF WORKS and thus condemning any and every type of justification that operates by the principle "of works." Rome is supremely ignorant of Biblical justification before God "of faith."
It is the utter denial of any kind of justification by the law "of works" (v. 28) that places both Jews and Gentiles on the SAME LEVEL before God (vv. 29-30) as there is no justification under the law of Moses by works any more than there is justification by works under the law of conscience given to the Gentile.
Hence, real justification by the law "of faith" - meaning faith "in" the propitiation/satisfaction provided by the life and death of Christ FOR THE UNGODLY BELIEVER is the only way the Law of God is not made "void" but is fulfilled/satisfied/propiatiated not by our works but by Christ works and thus the works of Christ "establish" the law of God (v. 31).
Rome vehemently repudiates this definitive passage because it totally exposes and condemns the whole soteriological fantasy embrace and practice by Rome.
The Word of God condemns any and all doctrines of justification that operate by the principle "of works" = meaning YOUR WORKS. Your works are consequential to justification before God but not causual (Eph. 2:10 "unto" good works). Your works may furnish EVIDENTIAL justification by faith but never the cause of justification before God. Rome confuses and mixes the works Christ provided for us with our works for Christ and thus confuse faith "in" God's provision for justification with our faithfulness to God because of justification by Christ.