Philippians 3:4

‘Though I myself might have confidence even in the flesh. If any other man thinks to have confidence in the flesh, I yet more,'

Paul then points out that if it came to ‘works of self-righteousness', then when he was a Jew he had had far more to rely on as making him acceptable to God than their present visitors, for he had been a Jew from his earliest days, and circumcised as such, had been of pure descent and training, and as a Pharisee had been as zealous after works of righteousness as it was possible to be. And the implication is that yet it had been insufficient. By this he is cutting the ground from underneath anyone who might suggest that they had some kind of superiority that others should follow. He had had that superiority, but it had failed him, and having come face to face with the risen Christ he had counted all his self-effort as worthless in contrast with knowing Christ, which he had discovered to be all that he needed.