The Judaizers who troubled the churches of Galatia were sent by Antioch to reform the churches founded by Paul.
The theory goes that one of Paul’s supporters came from Galatia to inform him of the plans of the Judaizers to move against Philippi, and the other Pauline churches.
There is a note of urgency, which penetrate the letter and the words are extremely harsh: ‘watch out for those dogs, those men who do evil, those mutilators of the flesh’ (Phil 3:2)