Paul writes to the Colossian church to relieve them of the burden false teachers have brought in, that Christ is not enough, he's only one part that leads to right relationship with God.  Paul reminds the church there is one Gospel and it is complete.   He encourages the church to be rooted and firm in this truth and to see old covenant religion for what it is, shadows of the reality Christ, and to denounce the futility of man made religion.  Colossians 2:6-23