Beware lest any man spoil you - The word “spoil” now commonly means, to corrupt, to cause to decay and perish, as fruit is spoiled by keeping too long, or paper by wetting, or hay by a long rain, or crops by mildew. But the Greek word used here means to spoil in the sense of plunder, rob, as when plunder is taken in war. The meaning is, “Take heed lest anyone plunder or rob you of your faith and hope by philosophy.” These false teachers would strip them of their faith and hope, as an invading army would rob a country of all that was valuable.
Through philosophy - The Greek philosophy prevailed much in the regions around Colossae, and perhaps also the oriental or Gnostic philosophy. See the Introduction They were exposed to the influences of these plausible systems. They consisted much of speculations respecting the nature of the divine existence; and the danger of the Colossians was, that they would rely rather on the deductions of that specious reasoning, than on what they had been taught by their Christian teachers.
And vain deceit - Mere fallacy. The idea is, that the doctrines which were advanced in those systems were maintained by plausible, not by solid arguments; by considerations not fitted to lead to the truth, but to lead astray.
After the tradition of men - There appear to have been two sources of danger to which the Christians at Colesso were exposed, and to which the apostle in these cautions alludes, though he is not careful to distinguish them. The one was that arising from the Grecian philosophy; the other, from Jewish opinions. The latter is that to which he refers here. The Jews depended much on tradition (see the notes at Matthew 15:2); and many of those traditions would have tended much to corrupt the gospel of Christ.
After the rudiments of the world - Margin, elements. See this explained in the Notes at Galatians 4:3.
And not after Christ - Not such as Christ taught.