Paul always starts off his message with a greeting and it doesn't surprise me that he even encourages the church of Corinth. At the same time he doesn't waste time before he begins addressing conflict amongst the other believers. Some follow after Paul, others after Apollos, and others might even follow the other disciples, but in the end we're all unified through Christ. Jesus didn't die individual deaths for each church or each member, but he died once for all so that we might be unified THROUGH him!