Read Philippians 3
While it doesn’t seem that there was a specific threat to the unity of the church in Philippi, Paul knows from experience that there are those both in the faith and outside of it who will come lurking eventually. We have seen this in his other letters as well to the church in Ephesus, the churches in Galatia, the church in Rome, and his multiple letters to the church in Corinth.
So Paul takes this opportunity to exhort the church in Philippi towards greater unity and the collective goal, that they may not be sidetracked by the “Judaizers” who preach circumcision or any other group that might try to push its way in.
Paul’s way of doing this, interestingly enough, is by citing himself as an example. Indeed he was the Jew of all Jews, a leader in the community before he met Christ on the road to Damascus. However, what Paul realized very quickly is that all of it was for nothing, and is not merely a distraction from the true goal of following Christ Jesus.
He talks about this in terms of a race, an apt metaphor if ever there was one. This isn’t, however, a 100M sprint, it’s a marathon. In other places, Paul talks about training his body for this long race, not getting distracted by those who would offer an “easy win.” I imagine it would be pretty tempting, in the middle of a 25K run, if someone offered a ride to the finish line. Essentially, that is what the Judaizers were doing, offering a physical act as the true way of Christian identity.
To this, Paul says no. Don’t take the ride, don’t listen to the lies. We press on toward the goal for which God has called us heavenward in Christ Jesus.