There’s a lot going on in this chapter. Translators note that this passage is loaded with ambiguous phrases, and too many English renderings follow a path that tends to obscure the depth of what Paul is saying.
As previously noted, the biggest issue is denying that Christ is the Son of God. Paul does not distinguish here between the Judaizer attack and the Gnostic one. It may well be that these two groups were working together in this particular region. Paul mentions Laodecia as part of the same community of faith. Even though none of these believers ever encountered the ministry of Paul firsthand, he still carries a heavy burden of concern for them simply because they belong to Christ.
He isn’t arming them for debate. Rather, he is prompting them to make the familial unity of Christians their single greatest defense. Stand together in your faith in Christ! What is this “mystery of Christ”? He conquered the flesh, and passed on to us His power to do so in our own lives. There is no mistaking that the denial of the flesh and this world is crucial to everything Paul says here. This is the real treasury of divine wisdom, not the nonsense cooked up by the philosophers and teachers of Judaism and Gnosticism.
It’s not about reasonable arguments; it’s about taking up your own Cross. This life is one big lie, and we must dismiss it in order to walk with Christ. But having received His Holy Spirit in our souls, we have everything we need to stand firm against any human reason. Paul does not attack erudition itself, but encourages his readers to make sure that the content of that profound knowledge is the truth Jesus taught.
Both Judaism and Gnosticism were rooted in the flesh, and the assumptions that this world is all there is. This is at least part of what Paul means in referring to the Aristotelian logical foundation, using the term “elementary” or “rudimentary” principles of this world. It flatly denies that Jesus could rise from death, because there was no Spirit Realm in which He could wait to reclaim His body, and no spirits to inhabit such a realm.
Starting in verse 9, Paul hammers once again on bold and clear statements of doctrine. There is no useful distinction between Christ and God. When Jesus walked on the earth, it was as much of the very Presence of God as this world could have — God in the flesh. And because He returned to the Father, His Spirit is able to live in all of us at the same time. There is no higher authority, so pay no attention to the Jewish or Gnostic appeals to lesser authorities. The God of Creation lives in us.
Then Paul refers to spiritual circumcision; not just a clipping of some small bit of skin, but detaching our spirits from our fleshly nature. The fleshly nature is not our real selves. The baptism ritual was a declaration of feudal submission to Christ; the symbol was that the flesh dies and our spirits are raised to join Christ in His resurrection.
His voluntary death on the Cross defeated the grip of flesh on our souls. He broke that power by His willingness to pay the awful price. We are no longer captives of our fallen natures. We participate in His life in Heaven. Then Paul shifts to legal terminology, referring to a writ of debt filed as a hostile action against us. That writ was nailed to the Cross and died with His flesh.
In so doing, He confiscated the weapons of every authority, in Heaven and on Earth, rendering them harmless against us. His victory over the fleshly nature put them to shame; all their claims on us were suddenly a laughingstock.
Now that our fleshly natures are dead, there is absolutely no sense in binding the flesh under all the legalistic rules of the Talmud or the ethics of Gnosticism. Why worship angels, when we have direct access to the Creator? This is what holds us together, a bond far stronger than the fleshly birthright claims of Jews. Their silly rules are nothing more than a racist ethnic pretense of belonging to a God that has disowned them. Their self-righteous attitude about their silly rules is all they have.