This is why I write these things when I am absent, that when I come I may not have to be harsh in my use of authority – the authority the Lord gave me for building you up, not for tearing you down.
NIV
So I write these things while I am absent from you, that when I come to you, I may not have to deal sharply in my use of the authority which the Lord has given me [to be employed, however] for building [you] up and not for tearing [you] down.
AMP
Therefore I write these things being absent, lest being present I should use sharpness, according to the power which the Lord hath given me to edification, and not to destruction.
KJV
We are glad whenever we are weak but you are strong; and our prayer is that you may be fully restored.
NIV
For we are glad when we are weak (unapproved) and you are really strong. And this we also pray for: your all-round strengthening and perfecting of soul.
AMP
For we are glad, when we are weak, and ye are strong: and this also we wish, even your perfection.
KJV