What does it mean to be a true Jew in the New Testament?

In Romans 2:28-29, Paul emphasizes that a true Jew is not merely one who is outwardly identified as such but one whose heart has been transformed by the Spirit. This inward circumcision signifies a change in heart and disposition, aligning oneself not with ethnic identity but with spiritual reality. The significance here lies in the concept of covenant and relationship with God—true worship and obedience come from the heart rather than external rituals. Thus, in the New Testament context, identities are defined by faith in Christ rather than ethnic lineage, aligning with Galatians 3:28, which states that there is neither Jew nor Gentile, but all are one in Christ Jesus.