"For grief according to God produces repentance for salvation without regret, but the grief of the world produces death" (trans. by Yung Suk Kim).
Here, Paul juxtaposes "grief according to God" (kata theon lupé) with "the grief of the world" (tou kosmou lupé). Part of what I wrote in my forthcoming commentary on 2 Corinthians (2 Corinthians: Contextual Critical Commentary by Cascade):
In Stoic society, showing grief/pain is considered weak, so people endure pain and go to die without hope. They are distressed, disconsolate, and dejected, yet they do not know what to do with their pain, which is left uncared as much as it suffocates them. So, tou kosmou lupé must be worldly grief that does not find hope in God. Without hope in the God of mercy, the end of pain would be death. Likewise, Paul says "worldly grief produces death" (2 Cor 7:10).Then, what is godly grief? I continue to write about it.