2 Corinthians 1:12-22

12Now this is our boast: Our conscience testifies that we have conducted ourselves in the world, and especially in our relations with you, in the holiness and sincerity that are from God. We have done so not according to worldly wisdom but according to God's grace. 13For we do not write you anything you cannot read or understand. And I hope that, 14as you have understood us in part, you will come to understand fully that you can boast of us just as we will boast of you in the day of the Lord Jesus.
15Because I was confident of this, I planned to visit you first so that you might benefit twice. 16I planned to visit you on my way to Macedonia and to come back to you from Macedonia, and then to have you send me on my way to Judea. 17When I planned this, did I do it lightly? Or do I make my plans in a worldly manner so that in the same breath I say, "Yes, yes" and "No, no"?

18But as surely as God is faithful, our message to you is not "Yes" and "No." 19For the Son of God, Jesus Christ, who was preached among you by me and Silas[a] and Timothy, was not "Yes" and "No," but in him it has always been "Yes." 20For no matter how many promises God has made, they are "Yes" in Christ. And so through him the "Amen" is spoken by us to the glory of God. 21Now it is God who makes both us and you stand firm in Christ. He anointed us, 22set his seal of ownership on us, and put his Spirit in our hearts as a deposit, guaranteeing what is to come.

The backstory: There were people who gained some influence in the Corinthian church who felt Paul was a threat, so they tried to discredit him. One of the things they said about Paul is that he wasn’t “eloquent” enough. Paul’s response is that you can sound very intelligent without having any clue what you are talking about.

The gospel is not merely words, he points out. When he preached it to them in his “simple” words, they understood it and their lives were changed by it. Had he used words that they couldn’t understand, then they would not have been changed.

More importantly, he points out, is that the way he lived his life was also part of the message. His integrity, which the Corinthian church was aware of, was proof of the power of the gospel. This “simplicity” that he was accused of was not something to be ashamed of, rather it was an opportunity for Jesus to shine instead of him.