Salvation
Romans 3:28
For we account a man to be justified by faith, without the works of the law.
Context of the passage
Paul argues that both Jews and Gentiles are justified through faith in Christ, not through observance of the Mosaic ceremonial law such as circumcision.
Catholic reading
Catholics agree no one is justified by the 'works of the law'—the Mosaic ritual observances like circumcision and dietary codes—apart from faith in Christ; this does not exclude the grace-enabled works of charity that James says accompany living faith.
Common objection
'Works of the law' means all human works whatsoever, so this verse alone establishes sola fide against any Catholic contribution of works to justification.
Response
Throughout Romans, 'works of the law' consistently refers to Mosaic identity markers (circumcision, Sabbath, food laws, cf. Rom 3:29-30 which ties it to Jew/Gentile equality), not to good works in general, which Paul elsewhere insists God will judge and reward (Rom 2:6-8).