Paul's purpose is to refute the Colossian heresy. To accomplish this goal, he exalts Christ as the very image of God (1:15), the Creator (1:16), the preexistent sustainer of all things (1:17), the head of the church (1:18), the first to be resurrected (1:18), the fullness of deity in bodily form (1:19; 2:9) and the reconciler (1:20-22). Thus Christ is completely adequate. We "have been given fullness in Christ" (2:10). On the other hand, the Colossian heresy was altogether inadequate. It was a hollow and deceptive philosophy (2:8), lacking any ability to restrain the old sinful nature (2:23).
The theme of Colossians is the complete adequacy of Christ as contrasted with the emptiness of mere human philosophy.