2 Corinthians 7:8-9

For even though I did grieve you with my letter, I do not regret it [now]; though I did regret it —for I see that the letter hurt you, though only for a little while— yet I am glad now, not because you were hurt and made sorry, but because your sorrow led to repentance [and you turned back to God]; for you felt a grief such as God meant you to feel, so that you might not suffer loss in anything on our account.