Discussing 1 Corinthians 4:14-16, he gets close to the heart of the problem Paul was addressing in Corinth, and also how that underyling problem makes the letter relevant today:
Some teachers have …
“risen up in the church, ‘as if Paul were not intending to return to Corinth’ (verse 18). Apparently they have said to themselves, ‘Paul is not returning to Corinth. The church is ours. Now we can teach what we like.’
“In short, it was hoped, by some at least, that the church in Corinth would no longer be a ‘Pauline’ church, that their church would be taken out of his network of churches. In my view this is ‘the Corinthian error’. I say ‘is’ rather than ‘was’ since it is very common today. It is the error of rejecting Paul’s authority as an apostle to direct the faith and behaviour of the churches. The Corinthians had a faulty grasp on many things, for example, their compromise with pagan sexuality and idolatry (5:8-10), their love of law courts (6), their crass individualism (1, 12-14), and their disbelief in the coming resurrection of the dead (15). But these were but symptoms of a deeper illness, a refusal to submit to the authority of the apostle to the Gentiles.
“This is also very common today. Many in the churches look to the Gospels, but downgrade Paul, using only passages like the chapter on ‘love’ in 1 Corinthians chapter 13. The modern problem with Paul was the Corinthians’ ancient problem with Paul, that is, his directness of teaching about being a Christian in a pagan environment, which ours in the developed world has become. This is a failure to grasp the differing functions of a Gospel as opposed to a Letter. A Gospel has a narrow goal, to inform readers about Jesus, his life and the teachings he gave in the context of Galilee and Judaea, and to call for repentance and faith. The Letters of the New Testament, however, address a breadth of day-to-day issues in the churches, including the churches of the Gentiles were different problems were encountered from those in the Jewish churches. By their nature the Gospels, as biographies of Jesus set in a Jewish context, simply do not address issues with the specific directness of Paul’s Letters which were addressed to readers in a world of rampant idolatry and sexuality. But we must be in no doubt that the writers of the Gospels would have had exactly the same views as Paul on matters where his views are objected to.”
(That's from page 73 in my edition, but the edition currently in print may have different page numbers)
For further reading, you may wish to remind yourself of an extended quotation from CS Lewis.