This is a really quite strong. ‘Utterly’ means a total fault, and the word translated fault means failure or defeat.
It is a matter of sorting out in our minds what is most important. Is it most important that I protect my own rights and stand on my own dignity, even if it brings harm to the church? Faith will conclude that God will never allow those who are concerned for his honour to be truly and permanently disadvantaged. He notes all wrongs done to us and he will come to our defence. Should I be afraid of letting others take advantage of me, and doing nothing to defend myself? Well, certainly we should be concerned about the conduct within the local church, but these things should be settled by those who mature believers in the church. But Paul says that we should let ourselves suffer wrong rather than bring the conduct of the church into disrepute before the world. Of course this assumes that the church concerned is holding on to the truth of the gospel and has not become apostate. How often he suffered unreasonable behaviour from the churches! How patiently he put up with it! He would rather suffer great injustice than to let the church come under the scorn of the world for its conduct.