Paul wrote the First Letter to the Corinthian Church in order to

a. reaffirm his love for them, since it had been so long since his last visit, and to answer the questions they had sent him.
b. explain his gospel to a church founded by a different apostle and on a different gospel, probably Peter's, in order that he might earn their acceptance and financial support
c. explain why he could not be with them as planned, since he was at the moment imprisoned, but he would stop and stay with them for a while on his way to Spain
d. encourage unity among all of the factions breaking out among members and to address many complaints of immoral behavior
e. report on his fallout with the church members, their rejection of him during a visit, including a physical attack against him there, and his hope that they will accept his gospel again and his authority to teach it