On this day, the church celebrates the commemoration of the circumcision of the Lord Christ, to Whom is the glory. God had ordained the law of circumcision as a sign that His people would become a particular people over all others. This was that every male of the seed of Abraham be circumcised on the eighth day of his birth. God put every soul that did not obey this law under judgment.
As our Lord Jesus was born from the posterity of Abraham, according to the flesh, He willed to be circumcised on the eighth day, to fulfill the law of and to relieve us from the heavy burden of this commandment, as St. Paul says, "Now I say that Jesus Christ has become a servant to the circumcision for the truth of God, to confirm the promises made to the fathers." (Romans 15:8)
He also gave us the sign of the new covenant through baptism, as St. Paul says, "In Him you were also circumcised with the circumcision made without hands, by putting off the body of the sins of the flesh, by the circumcision of Christ, buried with Him in Baptism in which you also were raised with Him, through faith in the working of God, Who raised Him from the dead. And you, being dead in your trespasses and the uncircumcision of your flesh, He has made alive together with Him, having forgiven you all trespasses." (Colossians 2:11-13)
Therefore, He demands from us to keep the spiritual circumcision, that is to say the circumcision of the heart, so that we may live for Him in righteousness and in holiness, for He says, "Unless one is born of water and the Spirit, he cannot enter the Kingdom of God." (John 3:5)
Glory be to our God forever. Amen.