Justification To Life, No Part of Works...

"Although eternal life was, in the covenant of works, promised to Adam and his posterity on condition of his perfect obedience, and that only, yet a man is to be counted a legalist or self-righteous if, while he does not pretend that his obedience is perfect, he yet relies on it for a title to life. Self-righteous men have, in all ages, set aside as impossible to be fulfilled by them that condition of the covenant of works which God had imposed on Adam, and have framed for themselves various models of that covenant which, though they are far from being institutions of God, and stand upon terms lower than perfect obedience, yet are of the nature of the covenant of works. The unbelieving Jews who sought righteousness by the works of the law were not so very ignorant or presumptuous as to pretend to perfect obedience. Neither did those professed Christians in Galatia who desired to be under the law, and to be justified by the law, of whom the apostle therefore testified that they had "fallen from grace' (Galatians 5:4), presume to plead that they could yield perfect obedience. On the contrary, their public profession of Christianity showed that they had some sense of their need of Christ's righteousness. But their great error was that they did not believe that the righteousness of Jesus Christ alone was sufficient to entitle them to the justification of life; and therefore they depended for justification partly on their own obedience to the moral and ceremonial law. It was this, and not their pretensions to perfect obedience, that the apostle had in view when he blamed them for cleaving to the law of works, and for expecting justification partly on their own works of obedience to the moral and ceremonial laws, they and the apostle informed them, were fallen from grace; Christ had become of no effect to them. And they were "debtors to do the whole law" (Galatians 5:3-4). By depending for justification partly on their imperfect obedience to the law, they framed the law into a covenant of works, and such a covenant of works as would allow for imperfect instead of perfect works; and by relying partly on the righteousness of Christ, they mingled the law with the gospel and works with faith in the affair of justification. Thus they perverted both the law and the gospel, and formed them for themselves into a motley covenant of works."

John Colquhoun, A Treatise on the Law and Gospel pp. 18-19.