The most subtle form of legalism appears in our spiritual life. We think that if we pray more, witness to a great number of people or mechanically live the Spirit filled life, we will succeed spiritually. Obviously, we cannot have a dynamic spiritual life without these means. But if we confuse means with end calamity can come to our Christian life. Morality is not the same as spirituality.
Morality is man oriented.
Spirituality is God oriented. In verse 4 Paul made the point that when it comes to confidence in the flesh, he had an outstanding religious career. In this verse he delineates and documents his successes. He believed that these things would impress God. When he met the Savior he found they were liabilities.