But they measuring themselves by themselves, and comparing themselves among themselves, are not wise.
When we measure our righteousness by comparing it to the righteousness of others, or when we compare our relative badness or goodness to how others behave, we are not wise. We must compare ourselves only to Christ. How do we measure up? We fall short. Only the Lord Jesus has the perfect standard. We can’t even compare ourselves to Paul or Peter or John. No, we must relate everything to the standard that God has set - and it never changes.