Covenantal Merit
Not only is there a “great disproportion” between the works of the redeemed “and the glory to come,” but also an “infinite distance that is between us and God” (WCF 16.5). Even pre-fall merit is thus excluded, in any proportional sense, because of the ontological difference between the Creator and the creature. Adam had a capacity for perfect, personal, and perpetual obedience, but the value of that obedience was far less than the promised reward. Quite apart from the problem of sin, it seems, there was no possibility of Adam or his descendants accelerating an eschatological or glorified state by means of any real merit of his own; he could only do so through a covenantal arrangement, where God, in his benevolent freedom, would reward his obedience with a gift beyond that which he had earned.
Orthodox Presbyterian Church. “Report of the Committee to Study Republication.” Presented to the Eighty-third (2016) General Assembly. Accessed February 9, 2021. https://www.opc.org/GA/republication.html