What is required in order to keep the whole law?
Keeping the whole law requires the full system: a temple, a priesthood, an altar, and a flock of sheep for sacrifices. If one attempts to keep any part of the law, all of it must be kept, and that meant the entire sacrificial and priestly apparatus.
Les explains that the law was never given to save anybody, not even the Jew under it. Paul says in Galatians to stand fast in the liberty wherewith Christ has made us free and not be entangled again with the yoke of bondage. Les points out that as soon as someone says they are trying to keep the commandments, they place themselves under that yoke of bondage. Another Scripture says if you keep part of the law, you must keep all of it. To keep all the law, a person would need a temple, a priesthood, an altar, and a flock of sheep, because keeping the law meant sacrifices, a priesthood, and the whole system. Les also notes that when the age of grace came, God sovereignly had the temple in Jerusalem destroyed by the Roman armies, stone by stone, because the age of law had faded and grace had come in.