In 2:14ff. Paul has given a sustained defense for the legitimacy of his apostleship. He has already pointedly urged the Corinthians not to receive the grace of God in vain by rejecting his God-given apostleship (6:1). In 6:11–7:4 Paul turns once again to exhortation and, in the process, draws the whole apology to a fitting conclusion that recalls its beginning (this rhetorical device is called an inclusio). The appeal pivots on the word hearts, which Paul has used extensively in the course of his apology, not only in the context of his ministry of the new covenant (3:1ff.) but also as the only valid criterion for assessing Paul’s apostleship (5:12). Hence Paul exhorts the Corinthians to open their hearts to him, even as his heart is open to them and they are in his heart, explicitly referr…