Phil 3: 4-6
Circumcised the eighth day, of the stock of Israel, of the tribe of Benjamin, an Hebrew of the Hebrews; as touching the law, a Pharisee; Concerning zeal, persecuting the church; touching the righteousness which is in the law, blameless.
The ‘flesh’ here signifies a man’s earthly or worldly status, attainments, achievements, successes, inheritances (cultural, traditional); things that make us respectable and acceptable in the society; educational attainments; family background and name; personal achievements, social class to which we belong etc.
To have ‘confidence in the flesh’ therefore is to think that one is accepted by God on the basis of these worldly attainments. It is to think that one has a place with God and is recognized because of what he possesses. Therefore one boasts of such attainments.
The Pharisees for instance would boast of their devotion to the Law; they know it inside out and teach it well (though they didn’t apply it to themselves). So they thought by knowing and teaching and carrying the religious forms, God is well pleased with them as the custodians of the Law. They thought they had a standing with God because they treat the Law as sacred.
Another example is; a brother appointed as a leader may think that he now has a standing with God because of his position among the brethren. He may think that because he leads or has a pastoral oversight of the flock of God he has a special place with God.
The general conclusion is that privileged positions or worldly attainments will never confer on a man a special status with God. We have a special place and standing before God by faith in the Lord Jesus Christ through whom we have access into His grace and stand.