We have learned from the prophets, and we hold it to be true, that punishments, and chastisements, and good rewards, are rendered according to the merit of each man’s actions. Since if it be not so, but all things happen by fate, neither is anything at all in our own power. For if it be fated that this man, e.g., be good, and this other evil, neither is the former meritorious nor the latter to be blamed. And again, unless the human race have the power of avoiding evil and choosing good by free choice, they are not accountable for their actions, of whatever kind they be. But that it is by free choice they both walk uprightly and stumble, we thus demonstrate. We see the same man making a transition to opposite things. Now, if it had been fated that he were to be either good or bad, he could never have been capable of both the opposites, nor of so many transitions. But not even would some be good and others bad, since we thus make fate the cause of evil, and exhibit her as acting in opposition to herself; or that which has been already stated would seem to be true, that neither virtue nor vice is anything, but that things are only reckoned good or evil by opinion; which, as the true word shows, is the greatest impiety and wickedness. (APOLOGY #1, Justin Martyr, CA 160 AD)
It is the general consensus of the reformers that man is incapable of possessing any merit before God. Luther writes in his commentary of
But because of your hard and impenitent heart you are storing up wrath for yourself on the day of wrath when God's righteous judgment will be revealed. He will render to each one according to his works: to those who by patience in well-doing seek for glory and honor and immortality, he will give eternal life; but for those who are self-seeking and do not obey the truth, but obey unrighteousness, there will be wrath and fury.
Luther might equally pull out
For if Abraham was justified by works, he has something to boast about, but not before God. For what does the Scripture say? "Abraham believed God, and it was counted to him as righteousness."
It is here that we must carefully understand the differences between the ancient church of the first millennium and the medieval errors that produced Luther’s rebellion. Luther had been indoctrinated in the kind of medieval Catholicism that taught the children of the church that they must posses a merit of their own, and then couple that merit with the atonement of Jesus in order to be found acceptable to God. This is called the doctrine of “condign merit.” And he was right to rebel against such teachings. However, Justin knew nothing of condign merit; instead he understood that in Christ, God now lives in each believer by way of the Spirit of Christ, and that the Spirit’s gift to us is to produce the works of Christ, which are not only merit filled but also ours. At the same time, he also knew that each believer is also capable of resisting the Holy Spirit, and thus able to merit evil judgment. If this were not so there would have been no need for him or the prophets to whom he refers to warn the church about such matters. In summary, the church Fathers saw human merit is nothing less than the works produced by the Spirit in us, and yet because we carry them out they are our works by which our faith will be judged.