Apostle Paul's preaching made the Corinthians to feel sorry for their sins and they repented. Godly sorrow brings life (salvation) and worldly sorrow brings death. When a teaching makes you to move closer to God and hate sin with a passion, it is from God. But if someone teaches you not to repent of your sins (deeds of the flesh) beware of such a teaching. It is not the gospel of grace.
(Meditation thought from 2 Corinthians 7th chapter)
