Circumcision was always to be more than just outpatient surgery without the benefit of anesthesia. It was an outward sign of the covenant and the symbol of an inward piety. God said “circumcise your hearts and don’t be stiff-necked any longer (10: 16). God promised that in the day He restored the fortunes of Israel that He would circumcise the hearts of the nation (30: 6). Because circumcision pointed to a deeper reality, Moses could speak of his “uncircumcised lips” (Ex. 6: 12 literal translation). Circumcision, rightly considered, symbolized the fact that the thick foreskin of the heart had been cut away leaving the Israelite highly sensitive to his God. It illustrated, then, something already true in the heart of the Israelite.
Baptism is a similar sign of the covenant for the New Testament believer. In Him you were also circumcised with a circumcision not done with hands, but putting off the body of flesh, in the circumcision of the Messiah. Having been buried with Him in baptism, you were also raised with Him through faith in the working of God, who raised Him from the dead. And when you were dead in trespasses and in the uncircumcision of your flesh, He made you alive with Him and forgave us all our trespasses (Col. 2: 11 – 13). Baptism, for the believer, is more than a public bath with your clothes on. It represents that our sins have been stripped away by the cutting, converting work of the Christ.
When the Israelite sinned after circumcision, he made a mockery of the entire process suggesting that nothing inward had really taken place. So it is with the Christian. When we sin defiantly after our baptism, we call into question whether anything has happened deep in our heart.
Baptism is a more significant symbol than circumcision because it pictures more. Baptism pictures more than just our death to self (which circumcision also did). Baptism also portrays the death, burial and resurrection of Jesus Christ and our co-death, co-burial and co-resurrection with Him (Rom. 6: 3 – 6; Col. 2: 11 – 13). Having been baptized we are to live like we have truly died and risen again.