What does 2 Corinthians 7:8 mean?

At some earlier date, Paul had written a severe and corrective letter to Christians in Corinth. During his last "painful" visit with them, they sided with someone among them who stood against Paul in some way. The details are not clear, but Paul considered their action as sinful and perhaps a personal betrayal of their relationship with him.

He sent Titus to Corinth to deliver this rebuke and instruction to repent. Titus had now, finally, returned and reported that the Corinthians had, in fact, repented. They mourned over their sin after reading Paul's letter to them.

Paul has two reactions to hearing about their sadness in response to his rebuke. Like a loving parent, he hates to hear that they were sad, but he also understands their sadness to be a sign of genuine repentance from wrongdoing. So, he declares both that he does not regret writing the letter, since it led to repentance, but that he did regret hurting them in this way because of his affection for them. He is glad that their sorrow lasted only for a short time and achieved its purpose.

He writes in the following verses that this is exactly how godly repentance is supposed to work: sadness for a moment followed by restoration and a renewed commitment to doing what is right.