" 9 For in him the whole fullness of deity dwells bodily, 10 and you have been filled in him, who is the head of all rule and authority. 11 In him also you were circumcised with a circumcision made without hands, by putting off the body of the flesh, by the circumcision of Christ, 12 having been buried with him in baptism, in which you were also raised with him through faith in the powerful working of God, who raised him from the dead. 13 And you, who were dead in your trespasses and the uncircumcision of your flesh, God made alive together with him, having forgiven us all our trespasses, 14 by canceling the record of debt that stood against us with its legal demands. This he set aside, nailing it to the cross. 15 He disarmed the rulers and authorities and put them to open shame, by triumphing over them in him."
Colossians 2:9-15
It must be emphasised that the various 'pictures' of redemption which Paul highlights here are different aspects of the same reality, different and complementary facets of the same jewel. It's almost as if Paul is viewing Christ and His redemption through a camera and by so doing he shows us these different camera angles so that we will get the full, thrilling picture.
In his first 'picture' of redemption, Paul uses circumcision as the gruesome metaphor for the crucifixion of the body of flesh/the old man in the death of Jesus Christ on the Cross (2:11). Paul is speaking in objective categories: He refers to this destruction of the body of flesh as having occurred, once and for all, in Christ. What Paul is saying then is that in the death of Christ on the Cross at Calvary the 'body of flesh' was stripped away once and for all. In Christ's death the old man/old fallen Adam/sinful humanity was cut off and destroyed once and for all time and for all people. Now Paul is saying something very profound here about the person and work of Christ. The background to this atoning circumcision is the Incarnation. When Christ was incarnate of the virgin Mary, by the Holy Spirit, He assumed a body of flesh: 'Our God contracted to a span, incomprehensibly made Man' became The Man Christ Jesus, having our flesh and our nature. He came to redeem fallen mankind and he stooped to the lowest to lift us up. The Incarnate Word of God took to himself human flesh and nature in all of its fallen sinfulness and he sanctified it. As the new Adam, he took up what the old Adam had spoiled and corrupted, he took up this old sinful humanity of ours and throughout his life he subdued and mastered it, living as the sinless one, perfectly obedient to the Father. Ultimately, he took this 'body of flesh' to death and it was crucified and in the circumcision of his death, finally and fully, the old man/the body of sin was stripped/cut off.