Here is where Paul gives the clearest expression to the theme of the letter: strength in weakness. This text is not only the climax of 2 Corinthians, it is arguably the climax of 1 and 2 Corinthians. It reminds us of the very heart of Christianity. When Jesus said to Paul, "my grace is sufficient for you," how was he reminding him not only of the gospel, but of the core principle of the entire Christian life?