Paul wrote 2 Corinthians to defend his ministry and apostleship after being criticized by false teachers in the Corinthian church. The letter outlines the steps leading to Paul writing it, including his previous visits and letters to Corinth. It contrasts with 1 Corinthians in focusing more on Paul's personal experiences and emotions. Paul defends his ministry, credentials as an apostle, and encourages the Corinthians in areas like giving, before giving his final exhortation.