2 Cor. 11:5-6 (ESV)
I consider that I am not in the least inferior to these super-apostles.  Even if I am unskilled in speaking, I am not so in knowledge; indeed, in every way we have made this plain to you in all things.
Rhetoric is persuasive. Paul makes the claim often that he was not a good speaker, at least not as good as others. Paul though, gave pen to some of the most memorable of passages, take 1 Corinthians 13 for instance. It seems though that many of the better rhetoricians used their skill to further themselves rather than the gospel. Perhaps that is the real crux. The gospel is foolishness to the world. The brute reality of our condition must be exposed before the gospel will make any sense to us. And the brute reality of our condition is not pretty. We are sinners, we are evil, we are wicked. That is the brute reality. When was the last time you heard T.D. Jakes, or Joel Olsteen say anything close to that.
Paul here emphasizes that it isn’t how things are being said that matters, but what is being said. In other words, doctrine, contrary to popular opinion, does matter. The mind does matter. It is not so much that you believe, but what you believe. Pay attention to the content of the message. Does it teach Jesus Christ and Him crucified? Does it point you to the cross? Or is it telling you that you are good and salvation is within your grasp? Is it the gospel, or is it “The Little Engine that Could”?