What was the main purpose of Paul's first letter to the Corinthians?
Paul's first letter to the Corinthians was written mainly to correct serious problems in that local assembly, especially gross immorality. A church member was guilty of immorality so severe that even pagan Gentiles did not practice it. The letter addressed these terrible things occurring among the Corinthians.
Les explains that the first letter to the Corinthians was a letter that had to correct some horrible problems among the Corinthians, chief of which was gross immorality. It was so gross that even the pagan Gentiles did not do it, yet a member of the Corinthian church was guilty. So the main thrust of the first letter was to correct terrible things going on in that local assembly. The second letter then comes within the next year, perhaps ten or eleven months later, though scholars do not agree on the exact timing.