# Because I was confident about this

The word "this" refers to Paul's previous comments about the Corinthians. Paul explains his sincere expectation with pure motives to come see the believers in Corinth after his first letter. People were criticizing Paul and saying he was not sincere. He refutes them by explaining his motives for what he was doing.

# so that you might receive a second favor

"so that you might benefit from me visiting you twice"