Later, as a Christian, Paul looked back on his old Judaism and saw exactly why it had failed.
Israel who pursued a law that would lead to righteousness did not succeed in reaching that law. Why? Because they did not pursue it by faith, but as if it were based on works (Romans 9:31-32).
Brothers, my heart’s desire and prayer to God for them is that they may be saved. For I bear them witness that they have a zeal for God, but not according to knowledge. For, being ignorant of the righteousness of God, and seeking to establish their own, they did not submit to God’s righteousness (Romans 10:1-3).
As Paul showed in Philippians 3:6, he was as good as anyone at establishing his own righteousness. We might say that he built higher than most Jews against the wall of sin. Then he realized the truth of Christ. Paul saw the futility of all that construction on the wall. He climbed down from his scaffolding—from all the credentials and achievements he had built up. He abandoned his home by the wall. He gave up any claim to “a righteousness of my own that comes from the law.” Instead He turned to God’s solution. “Through faith in Christ” he received “the righteousness from God” (Philippians 3:9).
In Paul’s vocabulary “works” is usually (but not always) a word that summarizes Judaism’s method of salvation. “Faith” is often his key word for the Christian approach. When we see the difference between the two, we recognize the significance of the early church’s greatest problem. This was the problem that spurred Paul to write so forcefully about faith and works.