…”one must make a distinction between the contents or substance of the law, and the purpose for which it was given. The contents or substance is identical to the demands of the covenant of works established with Adam, for:

  1. There is but one holiness, and therefore there can also be but one rule of holiness. The requirement held before Adam was perfection, and this is likewise the requirement of the law of the ten commandments.
  2. The requirement of the covenant of works is impressed upon man’s nature (Rom. 2:14-15). However, the law which is impressed upon man’s nature, is identical to the ten commandments, even though they are not equal in clarity. Thus, the requirements of the covenant of works and the ten commandments are identical.
  3. Eternal life was promised to Adam upon perfect obedience, which would also be the results upon the perfect obedience of the ten commandments. “For Moses describeth the righteousness which is of the law, That the man which doeth those things shall live by them” (Romans 10:5). The purpose for the giving of the law of the ten commandments is, however, entirely different from the purpose for which God gave the law to Adam. The law was given to Adam in order thereby to obtain life, but the law of the ten commandments was not given to that end, since no one is capable of fulfilling it.”

-The Christian’s Reasonable Service, vol. 3, pp.41-42

I am a Reformed Presbyterian. I offer all content as my own personal reflections. I am not a licensed minister.