Note 5 at 2 Cor. 8:20: Paul is trying to avoid anyone accusing him of stealing or misusing any of this money. The brother that he spoke of in the previous verse was chosen by the contributing churches to accompany Paul and his companions and see that the money was used for the intended purpose. Paul is the one who suggested this (1 Cor. 16:3).

As the apostle who brought the gospel to these people, Paul might have demanded that the people trust him, and they probably would have complied. But Paul wanted to not only be right in the sight of God, he wanted to be right in the sight of men also (v. 21).

It is not enough to have integrity before God only. And it certainly is not enough to have integrity before men only. We need to walk in a pure heart before God, but also walk above reproach in front of man as much as possible. It was wisdom on Paul's part to have these other brothers there to keep Paul straight. Paul didn't need them to keep him from sinning. He needed them to keep others from doubting his integrity (see ref. a, b, and c at vv. 20-21).