Recently, while sitting under the teaching of our Old Testament professor at RPTS, Dr. C.J. Williams, an insight into Scripture came to me that I had never noticed before. So I just had to share it!
Dr. Williams was lecturing on the spiritual significance of circumcision at our Westminster Conference. He reminded us that the sign of the Old Testament covenant with Abraham was never to be seen merely as an outer mark but as a deeply significant, spiritual sign. This bloody, painful act was to picture the need God's people had to have the sin of their hearts circumcised. He quoted these two following primary texts where God both calls for and promises to the descendants of Abraham heart circumcision.
And the Lord your God will circumcise your heart and the heart of your offspring so that you will love the Lord your God with all your heart and with all your soul, that you may live. -Deuteronomy 3o:6
Circumcise yourselves to the Lord; remove the foreskin of your hearts, O men of Judah and inhabitants of Jerusalem; lest my wrath go forth like fire, and burn with none to quench it, because of the evil of your deeds. -Jeremiah 4:4
Clearly, in these texts, the Lord both promised and commanded Israel to undergo heart circumcision. He was promising to remove the sin from his people and their descendants, and He was commanding them to do so. He would divinely act by His Spirit's power to bring them to the conviction of their sin, and then by His Spirit's power expect them to obey His command to forsake their sins. This divine action is what happens when people come to repent of their sin and trust the Lord for its removal from their lives. Circumcision represented what Jesus Christ, the seed of Abraham (Gal. 3:16), accomplished as He died upon the cross and was raised from the dead.
As I reflected on what Dr. Williams was teaching, my mind was drawn to a New Testament text I had just lectured on before him. In a talk on the marks of the church and how baptism is the appropriate response to believing in the gospel, I referenced Acts 2:37.
Now when they heard this they were cut to the heart, and said to Peter and the rest of the apostles, “Brothers, what shall we do?”
At that moment, I realized that at Pentecost the Lord was fulfilling His promise to do this heart circumcision as these Jewish people gathered in Jerusalem had their hearts cut by the message of the gospel! I have since learned that others have certainly had this insight before me, but it is always special and keeps me in childlike awe when I keep seeing new connections in God's holy Word. That this conviction by Peter's hearers was a heart circumcision at Pentecost is further confirmed by what he then tells them.
And Peter said to them, “Repent and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins, and you will receive the gift of the Holy Spirit." -Acts 2:38
Just as the promise the Lord would bring a heart circumcision to His people is confirmed by the people at Pentecost having their hearts cut with the gospel, so is His command for the people to repent associated with the Old Testament call for them to circumcise their hearts.
And for those of us who believe that these covenant promises come to us fully and are represented visibly in the New Testament, we see an even greater correspondence.
As we know, the Lord had His people circumcise their children because the promise of heart circumcision extended to them as well, as Deuteronomy 30:6 quoted above states. So at Pentecost, as Peter calls the people to respond in repentance and faith to the gospel, he also calls them to be baptized as the New Testament sign of this heart circumcision. But he does not stop with just his immediate hearers. He reminds these new believers, who by faith in Christ are now truly sons of Abraham and heirs according to promise (Gal. 3:6-9, 29), that the gospel hope extends to their children as well.
For the promise is for you and for your children and for all who are far off, everyone whom the Lord our God calls to himself. -Acts 2:39
When Presbyterians baptize their children, they should be doing so in Abraham-like faith that the Lord will, in His timing and by His Spirit, perform this wondrous heart circumcision on them. Praying these promises gives Christian parents a great hope.