What did Titus find when he came to the church at Corinth, and what changed them?
Titus found a carnal, unspiritual congregation at Corinth, with many members still acting unspiritually. The letter of first Corinthians changed them, because Paul directly addressed their issues and told them to deal with them. This enhanced Paul's ministry, the congregation, and Titus.
Les explains that Titus, a new believer and student of Paul, came into the Corinthian situation and realized their carnality and how unspiritual many of the members were. Yet because of Paul's first letter to the Corinthians, the whole congregation changed—Paul took the bull by the horns, addressed the issues, and told them to deal with it. This not only enhanced Paul's ministry but also enhanced the congregation and Titus. These believers had been pagan idolaters and immoral, but after believing the gospel they became new creations in Christ Jesus, and they were a thrill to Paul and Titus.