In Chapter 2, verses 5-11, Paul is giving them an example of the Messiah himself as a positive example of One who walked in humility, not claiming His Jewish ness, just because He was born into Judaism which does not save anyone, including Himself. (Yahushua) These folks were evidently boasting about their conversion.
In the Philippians letter, Paul is dealing with folks who call themselves Jews, but are not. These folks were Gentiles whom had converted in their mind, rather than their heart and were preoccupied with physical circumcision , rather than the cutting of the hearts flesh. They were radical about their new found belief.
Circumcision was widely confusing back then because folks misunderstood it as initiation into the people of God. (the family) This is why Paul asked the question, “Are they Jews? If so, they are Jews only by conversion, while I am a Israelite by birth.” (Paraphrased)
This is why Paul said that he had no confidence in the flesh. He was giving them a comparison that he was a Jew by birth and now by faith, when they were claiming their conversion in boast, Paul was not. As Paul points out in verse 8, he doesn’t even put any weight into the fact that he was born a Jew. Kinda letting them know that they shouldn‘t be boasting about their conversion either. Paul was pointing out that either being born a Jew or the conversion into Judaism gave no one any spiritual advantage what so ever. Simular to any religious entity nowadays. Just because one is born into a Christian family doesn’t make one a Christian, anymore than going to McDonalds makes one a cheeseburger.
Heb 11:6 But without faith it is impossible to please him (Him): for he that cometh to God must believe that he (He) is, and that he (He) is a rewarder of them that diligently seek him (Him).
On the contrary, the spiritually circumcised are those who have ‘circumcised hearts and ears’ who have the foreskin of their old nature removed, cut away. We boast Paul says, in the Messiah Yahushua, not in our human qualifications. They could not have an outward conversion with out the inward change and they were not boasting of the latter.
Here it is in a nutshell ok? A believing Gentile, spiritually circumcised but physically un-circumcised, have been grafted into Israel by faith so that the promises of Abraham apply to those who come believing by faith. But just as Abraham kept covenant, so should those who come to the same God as Abraham, if they too expect to be in covenant with the God of Abraham.
It is like Paul said, we are to be obedient unto death so that we may be resurrected from it, death.
Php 3:10-11That I may know him, (Yahushua) and the power of his (Yahushua’s) resurrection, and the fellowship of his sufferings, (Yahushua’s sufferings) being made conformable unto his death; (Yahushua‘s death) If by any means I might attain unto the resurrection of the dead.
We have to die to ourselves and unto His death, in our stead that we have any hope. It is to this mark of obedience that we keep pressing forward to that end goal. We keep trusting and placing our faith in Yahushua, in the person and power of the Son of Yahwey. When Paul says, “Brethren, be followers together of me, and mark them which walk so as ye have us for an ensample“, he is calling them into this unity of faith. To walk as Yahushua walked and now as Paul is a follower thereof. Paul did not walk in the belief that he would make it to the end of his race, purely because he was a Jew, inward or outward. Paul gave all credit to the One whom he followed.