2 Corinthians 7:8-11 ESV
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. 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.
For godly grief produces a repentance that leads to salvation without regret, whereas worldly grief produces death. 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.
ESV: English Standard Version 2016