How do we know that believers are the true circumcision?

In Philippians 3:3, Paul describes true believers as the true circumcision, highlighting three distinctive qualities that set them apart. First, they worship God in the spirit, which indicates that their worship is genuine and heartfelt, not merely a matter of external rituals. Second, they rejoice in Christ Jesus, signifying that their joy and hope are found solely in Him and His finished work on the cross. Third, true circumcision means having no confidence in the flesh, illustrating that their salvation and standing before God are not based on personal achievements or adherence to religious laws but on the grace of God alone. This trio of characteristics defines what it means to be part of God's covenant people.