2 Corinthians 7:7-10

7and not only by his arrival, but also by the comfort he had received from you. He told us about your longing, your mourning, and your zeal for me, so that I rejoiced all the more.

8Even if I caused you sorrow by my letter, I do not regret it. Although I did regret it—for I see that my letter caused you sorrow, but only for a short time— 9yet now I rejoice, not because you were made sorrowful, but because your sorrow led you to repentance. For you felt the sorrow that God had intended, and so were not harmed in any way by us. 10Godly sorrow brings repentance that leads to salvation without regret, but worldly sorrow brings death.