The rhetorical questions are meant to affirm that Paul is not seeking to please people but God.1 This affirmation comes from the fact that he pronounces a curse on those who preach another gospel. He is not interested in living at peace with fellow believers
if those believers are denying the good news of Jesus Christ. It may be that Paul feels forced to make this statement because the distorters were saying that he relaxed the requirements of the gospel (circumcision and obedience to Mosaic laws) in order to win converts.2
10 For am I now seeking the approval of man, or of God? Or am I trying to please man? If I were still trying to please man, I would not be a servant of Christ.