Here are some points that no Roman Catholic can repudiate successfully:
1. The content of Justification is spelled out in Romans 4:6-8 which includes remission of sins and imputed righteousness.
2. That is the "blessing" which makes the man a "blessed" man.
3. This blessing was obtained by Abraham NOT IN CIRCUMCISION and thus not in circumcision as a "sign" or as a "seal." - Period!
Thus Roman Catholicism in its core soteriological belief is repudiated completely.
		
		
	 
the Roman Catholic dilemma with Romans 4-5:2 is that they must tie circumcision with justification in order to tie baptism with justification as they make circumcision under the Old Testament parallel to baptism under the New Testament but Paul denies any such literal connection.
Indeed, Paul's words "
NOT in circumcision but IN uncircumision" repudiates any attempt to move justification within the sphere of circumcision by any kind of literal connection or else the words "NOT in circumcision" are rendered void. 
Moreover, the Aorist tense verb "justified" demonstrates a completed action "in uncircumcision" while the perfect tense "stand" in Romans 5:2 shows that the only continuance beyond the intial completed actionof justification "in circumcision" is the perfected state of grace rather than any kind of justification that stands in need of completion. 
In order to confuse readers and in order to get around these grammatical and logical obstacles to Roman Catholic soteriology Roman Catholic exegetes fail to accuratley portray the logical developed argument in Romans 4:1-5:2.
However, the careful reader can easily see that Romans 4:1-3 introduces Abraham as the illustration with the declaration  there can be no boasting in justification by faith, whereas, Romans 4:4-5 deals with abstract doctrinal principle to reinforce the assertion that justification by faith provides no basis for boasting. In verses 4-5 which is the abstract doctrinal assertion, the verbs "believeth.....justifieth....imputeth" are all found in the present tense showing identical action with each other but in direct appliation to none other but  "the ungodly" demonstrating that such action are not consequences of imparted godliness or else that person could not be regarded as "ungodly."
In Romans 4:6-8 Paul appeals to the Psalmist to define the two necessary elements required for any sinner to be justified before God - imputed righteousness and remission of sins. Then in Romans 4:9 Paul begins the process of elmination whereby he eliminates various things that some would include in defining justification which concludes in Romans 4:22 followed by His application in Romans 4:23-25 and conclusion in Romans 5:1-2. 
In Romans 4:9-22 Paul eliminates sacramentalism (vv. 9-13); law keeping (vv. 14-15) and any definition of faith that includes any kind of assistance or participation on the part of the justified (vv. 16-22). 
The Roman exegete and every argument and conclusion they provide will always contradict four immutable contextual factors.  
1. Interpret justification so that it occurs "IN circumcison"
2. Deny the Aorist tense completed action "in uncircumcision"
3. Include what Paul excluded by elmination in vv. 9-22
4. Make Justification the consequence of imparted godliness instead of application to the "ungodly."