Paul starts this second letter by being cordial, but also defending himself a bit. It seems there has come a bit of a tension between him and the church. According to Craig Keener, the church may have thought Paul was a bit late in visiting, and Paul seems to think that the Corinthians needed a bit of a rebuke. Paul is defending his decision about travel, and you can be pretty sure that he’ll still correct them if he thinks they require it, since he is their spiritual father.