The Word of God is the pipeline for Spirit filling. This in turn results in obedience, fruit bearing, evangelistic zeal, compassion, and sanctification. It is also the only way to know the true gospel of grace. Therefore, Paul doesn’t trifle with enemies of the truth. The difference between weak teaching and false teaching is the difference between Twinkies and poison. Philippians is partly a clarion call for fidelity to the truth. So the tone at the beginning of Philippians 3 is confrontational and provoking because the truth was being attacked. Novelty Judaism and infatuation with Jewish traditions threatened new believers. Implying that pre-conversion works are necessary suggests you can earn grace. Any post-conversion works must be fruit of the Spirit, not acts of the flesh. On both counts the Judaizers failed. Paul calls them evil dog mutilators just to make sure there was no confusion. This is in stark contrast to his virtually lethargic attitude toward brothers who refuse meat, wine, and prefer to keep the Sabbath. In those cases it’s futile and foolish to escalate hostilities. We need to pick battles wisely, but when we go to war, fight to win.