Philippians 3:1-2
Finally, my brethren, rejoice in the Lord. To write the same things to you, to me indeed is not grievous, but for you it is safe.
Beware of dogs, beware of evil workers, beware of the concision.
Beware of those outside (the Church), beware of evil workers, beware of mutilators.
Those outside the Church can lead you outside the Church. There are dogs outside so stay inside.