Believer's Good Works: Evidence of Title to the Reward of Life

7thly. The two covenants differ as the order of acceptance. In the covenant of works acceptance began at the work, and then went on to the person. In the covenant of grace this order is quite inverted, acceptance beginning at the person, and then goes on to the work.

This difference naturally follows on what was observed respecting the conditions of the covenants, for, if works, or perfect obedience, was the condition of the first covenant, then that condition behoved to be performed before Adam could be accepted, and entitled to the reward. It was not sufficient that he had a righteousness of innocence: he behoved to have that of perseverance also, in order to the acceptance of his person. But as our works are not the condition of the second covenant, they cannot be the condition of our acceptance with God. They do not go before, but necessarily follow it. The end of Adam's obedience was to procure his title to the reward. That of ours is to evidence our title. His working could procure his acceptance, inasmuch as his person was not under a curse either before, or while he was working. His state was purely probationary, he being neither accepted nor condemned. He had also a sufficiency of strength to give perfect obedience, his nature being perfectly holy. But, ah! it is quite otherwise with us, both as to our persons and our nature. The one is already under a curse: the other totally polluted. Hence our works can never procure our acceptance. By the curse our persons are odious in the sight of divine justice, and if so, how can our works be acceptable? By the corruption of our nature we are without strength to give any holy, and therefore any acceptable obedience, for nothing but what is holy can be so. Therefore of necessity our persons must be accepted, and our nature changed before our works can be pleasing to God*."

Thomas Bell, A Treatise on the Covenant of Works and Grace, pp. 206-207. 
[emphasis added]