Paul's approach to false teaching in Colossians appears to be a little different to that found in some of his other letters (Galatians, Titus). This may well be because the false teachers were yet to infiltrate the church. But, since they have dogged his steps wherever he has gone, Paul gets his retaliation in first. And in doing so he presents the Colossians with an awesome description of the person of Christ and his cross-work. By making much of Christ Paul aims to show up these errors for what they really are.
Now, let us be clear, compared to Christ this alternative teaching and practice appears hollow, shallow, and pretentious. It makes much of religious behaviour, ritual and mysticism. Or in other words it makes much of human performance and appearance. And it is put back into the shadows by the majesty of Christ made fully known in the apostolic gospel.
Dick Lucas captures Paul's pastoral method in dealing with the error that threatened the Colossian church:
"This positive instruction, once its implications have been grasped in terms of the sufficiency of Christ, will be the Colossians' best protection against error."
So, how can you protect yourself against error? By following Paul's prescription in 2:6-7:
"Therefore, as you received Christ Jesus the Lord, so walk in him, rooted and built up in him and established in the faith, just as you were taught, abounding in thanksgiving."
James Buchanan summed up this pastoral approach in his classic work on justification:
"It has long been my firm conviction, that the only effective refutation of error is the establishment of truth. Truth is one, error is multiform; and truth, once firmly established, overthrows all the errors that either have been, or may yet be, opposed to it. He who exposes and expels an error, does well; but it will only return in another form, unless the truth has been so lodged in the heart as to shut it out for ever."
James Buchanan, The Doctrine of Justification, p. 15