Circumcise therefore the foreskin of your heart, and be no longer stubborn. Deuteronomy 10:16
Circumcision symbolized covenant, identity, and boundary. It marked who one belonged to. Physical circumcision without repentance invites judgment, because one becomes aware of sin without the remedy for sin.
Physical circumcision pointed forward to the cutting away of the "body of flesh" accomplished through union with Christ Jesus.
In Him you were also circumcised, in the putting off of your sinful nature, with the circumcision performed by Christ and not by human hands. Colossians 2:11
Lesson 24: Putting off the old sinful nature is fierce circumcision.