2 Corinthians 10:2, 6-11

yea, I beseech you, that I may not when present show courage with the confidence wherewith I count to be bold against some, who count of us as if we walked according to the flesh.

and being in readiness to avenge all disobedience, when your obedience shall be made full. Ye look at the things that are before your face. If any man trusteth in himself that he is Christ’s, let him consider this again with himself, that, even as he is Christ’s, so also are we. For though I should glory somewhat abundantly concerning our authority (which the Lord gave for building you up, and not for casting you down), I shall not be put to shame: that I may not seem as if I would terrify you by my letters. For, His letters, they say, are weighty and strong; but his bodily presence is weak, and his speech of no account. Let such a one reckon this, that, what we are in word by letters when we are absent, such are we also in deed when we are present.