Works of Sanctification - Reward found not in their merit...

Whatever value is indeed received in the works of sanctification by those who trust in Christ, it is accrued to them not by the spirituality or devoutness of their own righteous deeds, but rather on the basis of God's gratuitous grace.  And I might add that the grace of God in both our justification and sanctification in Christ is received solely by faith alone.

"Our third and last exception relates to the recompense of works,­ we maintaining that it depends not on their own value or merit, but rather on the mere benignity of God. Our opponents, indeed, admit that there is no proportion between the merit of the work and its reward; but they do not attend to what is of primary moment in the matter: that is, that the good works of believers are never so pure as that they can please without pardon. They consider not, I say, that they are always sprinkled with some spots or blemishes, because they never proceed from that pure and perfect love of God which is demanded by the law. Our doctrine, therefore, is that the good works of believers are always devoid of a spotless purity which can stand the inspection of God; nay, that when they are tried by the strict rule of justice, they are, to a certain extent, impure. But, when once God has graciously adopted believers, he not only accepts and loves their persons, but their works also, and condescends to honor them with a reward.

"In one word, as we said of man, so we may say of works: they are justified not by their own desert, but by the merits of Christ alone; the faults by which they would otherwise displease being covered by the sacrifice of Christ. This consideration is of very great practical importance, both in retaining men in the fear of God, that they may not arrogate to their works that which proceeds from his fatherly kindness; and also in inspiring them with the best consolation, and so preventing them from giving way to despondency, when they reflect on the imperfection or impurity of their works, by reminding them that God, of his paternal indulgence, is pleased to pardon it."

-The Necessity of Reforming the Church (1543), John Calvin.