John Calvin Commentary 1 Corinthians 6:5

"I say [this] to move you to shame. What, cannot there be [found] among you one wise man who shall be able to decide between his brethren," — 1 Corinthians 6:5 (ASV)

I speak to your shame. The meaning is — if other considerations do not influence you, let it at least be considered by you how disgraceful it is to you that there is not so much as one among you who is qualified to settle an affair amicably among brethren — an honor which you assign to unbelievers. Now, this passage is not inconsistent with the declaration we encountered earlier, when he stated that he did not mention their faults for the purpose of shaming them (1 Corinthians 4:14), for instead of this, by putting them to shame in this manner, he calls them back from disgrace and shows that he is desirous to promote their honor. He does not wish them, then, to form so unfavorable an opinion of their society as to take away from all their brethren an honor which they allow to unbelievers.