In the same book the same St. Ambrose says again: “Now if Peter fell, who said, ‘Though all men shall be offended, yet will I never be offended,’ who else shall rightly presume concerning himself? David, indeed, because he had said, ‘In my prosperity I said, I shall never be moved,’ confesses how injurious his confidence had proved to himself: ‘Thou didst turn away Thy face,’ he says, ‘and I was troubled.’” Pelagius ought to listen to the teaching of so eminent a man, and should follow his faith, since he has commended his teaching and faith. Let him listen humbly; let him follow with fidelity; let him indulge no longer in obstinate presumption, lest he perish. Why does Pelagius choose to be sunk in that sea whence Peter was rescued by the Rock?
Reproduced in full. Translation: Nicene and Post-Nicene Fathers, series 1, vol. 5 (Schaff, 1887), public domain (Public domain).