What is the significance of being spiritually circumcised?

In Philippians 3, Paul contrasts physical circumcision with spiritual circumcision, which signifies the heart transformation that occurs in true believers. This transformation is necessary as it signifies being made right with God through faith in Christ, rather than through outward observances. According to Romans 2:28-29, a true Jew is one inwardly, and this spiritual circumcision enables the believer to worship God in spirit and truth. It highlights the necessity of the new birth and the work of the Holy Spirit in conforming believers to the image of Christ.