2 Corinthians 7:5-16 (ESV)
5 For even when we came into Macedonia, our bodies had no rest, but we were afflicted at every turn—fighting without and fear within. 6 But God, who comforts the downcast, comforted us by the coming of Titus, 7 and not only by his coming but also by the comfort with which he was comforted by you, as he told us of your longing, your mourning, your zeal for me, so that I rejoiced still more.
8 For even if I made you grieve with my letter, I do not regret it—though I did regret it, for I see that that letter grieved you, though only for a while. 9 As it is, I rejoice, not because you were grieved, but because you were grieved into repenting. For you felt a godly grief, so that you suffered no loss through us. 10 For godly grief produces a repentance that leads to salvation without regret, whereas worldly grief produces death. 11 For see what earnestness this godly grief has produced in you, but also what eagerness to clear yourselves, what indignation, what fear, what longing, what zeal, what punishment! At every point you have proved yourselves innocent in the matter. 12 So although I wrote to you, it was not for the sake of the one who did the wrong, nor for the sake of the one who suffered the wrong, but in order that your earnestness for us might be revealed to you in the sight of God. 13 Therefore we are comforted.