You are judging by appearances. If anyone is confident that they belong to Christ, they should consider again that we belong to Christ just as much as they do.
References for 2 Corinthians 10:7
So even if I boast somewhat freely about the authority the Lord gave us for building you up rather than tearing you down, I will not be ashamed of it.
References for 2 Corinthians 10:8
I do not want to seem to be trying to frighten you with my letters.
For some say, “His letters are weighty and forceful, but in person he is unimpressive and his speaking amounts to nothing.”
References for 2 Corinthians 10:10
Such people should realize that what we are in our letters when we are absent, we will be in our actions when we are present.