Is it possible for a person to keep the whole law?
No, it is an utter impossibility for a person to keep the whole law. Only Christ, who walked this planet, was able to do so. Attempting to be justified by the law cancels the work of the cross and causes one to fall from grace.
Les explains that Paul testifies again that every man who is circumcised becomes a debtor to do the whole law. Circumcision was the big issue then, but Les points out it can be anything done in the energy of the flesh—joining the church, being baptized, taking the Lord's Supper, or good works—if tied to salvation, it cancels the work of the cross. God is adamant that He finished it, and if we are not satisfied with that, He is not accepting us. Only one person has walked this planet able to keep the whole law: Christ Himself. So it is an utter impossibility for anyone else. Paul adds that Christ becomes of no effect to those justified by law, and they have fallen from grace—not meaning they lost salvation, but that they turned their back on what God provided.
For I testify again to every man that is circumcised, that he is a debtor to do the whole law.
More Questions
Has anyone ever kept the whole law?
Only Christ has ever been able to keep the whole law, so it is utterly impossible for anyone else to keep it.