” This is My Covenant with you and your descendants after you, The Covenant you are to keep: Every male among you shall be circumcised. You are to undergo circumcision, and it will be The Sign of The Covenant between Me and you.” Genesis 17,10-11
In Genesis 17, God instituted the circumcision for all male descendants of Abraham from the age of eight days as A Sign of The Covenant between Him and Abraham and his offspring. To enter the Covenant, therefore, the flesh had to be circumcised.
However, in The New Covenant, the circumcision is rather that of the heart. When we receive The Word Of God with faith, it must pierce our hearts and make us feel pain just like pain felt during the circumcision of the flesh. This grief, this profound regret for having transgressed The Divine Laws, must produce a sincere and profound repentance of the heart. We are certainly saved by Grace, but The Lord uses our faith to do it. And faith can only be useful if it is active and produces repentance; otherwise it is a dead faith that serves no purpose and cannot benefit from Divine Grace.