For observe this very thing, that you sorrowed in a godly manner: What diligence it produced in you, what clearing of yourselves, what indignation, what fear, what vehement desire, what zeal, what vindication! In all things you proved yourselves to be clear in this matter.
The apostle Paul had strongly corrected the Christians in Corinth in his previous letter, and he had worried about their response (2 Corinthians 7:8). But he was relieved that their “sorrow led to repentance. For you were made sorry in a godly manner. … For godly sorrow produces repentance leading to salvation” (verses 9-10). He contrasted godly sorrow with worldly sorrow, which is basically just being sorry that you got caught.
In verse 11 Paul lists seven powerful components of godly repentance that lead to real change and salvation.
William Barclay wrote this comment about this passage: “A godly sorrow produces a true repentance, and a true repentance is one which demonstrates its sorrow by its deeds. The Corinthians proved their repentance by doing everything they could to mend the wretched situation that their thoughtless conduct had produced. Now they hated the sin they had committed, and even hated themselves for committing it, and they laboured to atone for it” (The Daily Bible Study Series, comments on 2 Corinthians 7:5-16).