“Concerning zeal, persecuting the church; concerning the righteousness which is in the law, blameless.”
The seventh and last asset that Paul declared before his conversion was about his own human righteousness.
“Concerning the righteousness which is in the law, blameless”
This is righteousness without God. It is a counterfeit righteousness. It is equivalent to the righteousness of v. 9:
“Not having my own righteousness, which is from the law.”
Paul kept up with his sacrifices. He was blamelessly scrupulous in keeping the sacrifices of the law. The law prescribed mechanisms for righteousness; Paul never failed to keep them. He was religious. However, he was religious but lost. To depend on anything but the blood of Christ is fatal. Paul did not say that he was perfect; he merely asserted his faithfulness to religion. He kept the ceremonial law perfectly.
The contrast here is between human righteousness and God’s righteousness. God’s righteousness can only be obtained by the sacrificial death of Christ.
Religion does not commend us to God; only the blood of Christ wins God’s favor.
Is your confidence in your religion or your Savior? Jesus finished all suffering that needed to be suffered upon the cross. He did it all; all to Him, we owe. Anything less than that is sinking sand. “On Christ, the solid rock I stand, all other ground is sinking sand.”