2 Corinthians 10:1…
They backslid before. What could prevent them from backsliding again?
Now, Paul would reiterate some of the basic principles of living according to the grace of God. (Things they had perhaps heard before, but failed to put into practice.)
Since Paul was still at a distance from the church at Corinth, his instruction was designed to preserve their repentance, which had been evidenced in Chapter 7. His sense was the same ingredients which had caused them to backslide before were still present at Corinth, and so his words are designed to encourage them to employ spiritual weapons available to them to defend themselves from the demonic influences which may cause them to backslide again.
His great reminder here is we do not walk, (we must not walk,) according to the flesh.
This had been their primary failure since Paul had departed from them. Once Paul left a series of pastors, speakers, evangelists and Judaizers came through the city and visited the church. It seems with each successive visitation new thoughts were formed and new comparisons to what Paul had taught had been made.
Some of the comparisons were related to gifting, as some of the speakers were regarded more powerful than Paul in delivering a similar message to Paul. This was threatening because it caused some of the body to be drawn to men rather than to the message of Christ. (What was dangerous then is dangerous now.)
Worse was once they were drawn to the oratory skills of speakers, they were prone to be drawn to the distorted messages of those opposed to Paul, who taught a different gospel than Paul taught. As a means of adding credibility to their teaching they sought to convince the church at Corinth that Paul was not an apostle at all – just another man peddling another message. (Their evidence of this was the fact Paul was: (A) a poor speaker, and (B) the things Paul suffered, and his visible poverty.) If he was truly an apostle of Christ – would God allow this?
To which Paul now reminds them their primary defense against this carnal reasoning and attraction which drew them away from the truth was spiritual not carnal. You must learn to be led by the Word of God and by the Holy Spirit alone, and not by the craftiness of men.
Secondly, you must learn to take your wandering thoughts captive by the power of the Holy Spirit. Any presentation – no matter how fanciful or inspiring – which draws your thinking even one iota or degree way from what the Word of God declares must be not be allowed to roam around in your brain.