John Calvin Commentary 2 Corinthians 8:22

"and we have sent with them our brother, whom we have many times proved earnest in many things, but now much more earnest, by reason of the great confidence which [he hath] in you." — 2 Corinthians 8:22 (ASV)

On account of the great confidence. The meaning is, “I am not afraid that their coming to you will prove vain and fruitless, for I have already felt an assured confidence that their mission will have a successful outcome; I am so well aware of their fidelity and diligence.” He says that the brother, whose name he does not mention, was more eagerly inclined, partly because he saw that the apostle had a good opinion of the Corinthians, partly because he had been encouraged by Titus, and partly because he saw many distinguished men devoting themselves to the same task with united efforts. Therefore, only one thing remained: that the Corinthians themselves should not fail to do their part.

In calling them the Apostles of the Churches, he might be understood in two senses: either as meaning that they had been set apart by God as Apostles to the Churches, or that they had been appointed by the Churches to undertake that office. The second of these is the more suitable. They are also called the glory of Christ, for this reason: that as he alone is the glory of believers, so he also ought to be glorified by them in return. Therefore, all who excel in piety and holiness are the glory of Christ, because they have nothing except by Christ’s gift.

He mentions two things at the end: “See that our brothers witness your love,” and secondly, “Take care that my boasting about you is not in vain.” For αὐτούς (to them) appears to me to be equivalent to coram ipsis (before them), because this clause does not refer to the poor, but to the messengers who had been mentioned. For he immediately afterwards adds that they would not be the only witnesses; rather, as a consequence of the report given by them, news would spread even to distant Churches.