Col 2:9-15 is the central passage in the Colossians epistle. Heresy provided false systems of spirituality by adding to the Gospel. We lack nothing in Jesus Christ. Col 2:13-15 Paul mentions 5 great works of God. Circumcision was a picture -- a foward looking sign -- of the results of faith (righteousness; removal of the flesh; Gen 17:1-27; Deu 19:12-16; Rom 2:25-29) in the Old Testament Rom 4:1-13. Baptism looks backward at our faith in Christ (Act 15:1-5; Rom 6:3-14).
Paul never met the Colossians but wrote to them from a Roman prison around 62 AD to counter misconceptions of his day. It magnifies the character of Jesus Christ more than any other book in the New Testament, and counters misconceptions of our day as well. The key verse may well be Col 1:18 "...that in all things, He might have preeminence."