Paul uses hamartia twice in the book of Colossians. In the first instance, he reminds the Colossians that they had redemption through the blood of Christ, a redemption that amounted to “forgiveness of sins” (1:14). The second use involves more metaphorical subtleties. He says in 2:11 that the Colossians had been circumcised with the circumcision made “without hands,” in the putting off the “body of the sins of the flesh.” The image clearly is that the foreskin represented the old corrupt man. But he then goes on to equate this with “burial in baptism” (2:12), something that represented the same spiritual operation — although in this case, instead of the foreskin being removed by circumcision, the dirt was removed by the washing with water.
This short passage is a stumbling block for many. But if we lay it out carefully, we can see how circumcision and baptism relate. The circumcision spoken off here is clearly spiritual circumcision (“without hands”), and refers to the circumcision of the heart by the Spirit of God (Rom. 2:29). From this we may conclude the same thing about the baptism — i.e. that it is the baptism of the Holy Spirit, the baptism of the heart. So spiritual circumcision is not being equated with physical baptism. Neither is physical circumcision being (directly) connected with physical baptism. But an indirect connect is being made.
Are spiritual circumcision and physical circumcision related? Yes, one is the sign of the other. Are spiritual baptism and physical baptism related? Again, yes. Are spirtual circumcision and physical baptism related. Obviously. What is to prevent us, Peter might ask in the presence of Cornelius, from drawing the last side of this square?