Now, who is so faultless among men, that God could always have him in His choice, and never be able to reject him? Or who, on the other hand, is so void of any good work, that God could reject him for ever, and never be able to choose him? Show me, then, the man who is always good, and he will not be rejected; show me, too, him who is always evil, and he will never be chosen. Should, however, the same man, being found on different occasions in the pursuit of both (good and evil) be recompensed in both directions by God, who is both a good and judicial Being, He does not change His judgments through inconstancy or want of foresight, but dispenses reward according to the deserts of each case with a most unwavering and provident decision.
Tertullian
The Five Books Against Marcion, Book II
Chapter XXIII