Will any one of you who has a servant plowing or keeping sheep say to him when he has come in from the field, ‘Come at once and recline at table’? Will he not rather say to him, ‘Prepare supper for me, and dress properly, and serve me while I eat and drink, and afterward you will eat and drink’? Does he thank the servant because he did what was commanded? So you also, when you have done all that you were commanded, say, ‘We are unworthy servants; we have only done what was our duty.’” (Lk. 17:7-10)
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. There will be tribulation and distress for every human being who does evil, the Jew first and also the Greek, but glory and honor and peace for everyone who does good, the Jew first and also the Greek. For God shows no partiality (Rom. 2:6-11)
Question 63. What! do not our good works merit, which yet God will reward in this and in a future life? Answer: This reward is not of merit, but of grace (Lk. 17:10) (Heidelberg Catechism, Q63)
... So then, we do good works, but nor for merit — for what would we merit? Rather, we are indebted to God for the good works we do, and not he to us, since it is he who "works in us both to will and do according to his good pleasure" (Phil. 2:13) — thus keeping in mind what is written: "When you have done all that is commanded you, then you shall say, 'We are unworthy servants; we have done what it was our duty to do.' (Lk. 17:10) ...
(Belgic Confession of Faith, Article 24)
One of the characteristic of Mono-covenantal Antinomianism is its denial of the idea of merit especially in the Covenant of Works. As opposed to its opposite number, Mono-covenantal Legalism as found in the heresy of the Federal Vision, the very idea of merit sickens the Mono-covenantal Antinomians, who see the idea of merit as leading to a form of works-based religion as epitomized in the Federal Visionists. In the battle within the two sides, the balance of the right preaching of the Law and Gospel are lost by both. In the camp of the Mono-Covenantal Legalists, Gospel becomes Law, and thus their idea of gospel is made up of commandments of doing and believing. In the camp of the Mono-Covenantal Antinomians, Law becomes Gospel, and thus the Law lose much of its power of warning, condemnation and exhortation. Instead, the Law mostly becomes something we are reminded of so that we can run back to God's grace (which is certainly correct but not enough). The motivation for living holy lives has been greatly reduced, and warnings against apostasy and carnality muffled since after all, aren't we justified by God's grace apart from works?
In this post therefore, I would like to address the error of the Mono-Covenantal Antinomians in their rejection of the concept of merit especially in the Covenant of Works, especially in the interpretation of Lk. 17:10 and in the Continental Reformed Belgic Confession and Heidelberg Catechism. It must be noted here that both sides of the mono-covenantal spectrum reject the Covenant of Works, the Legalists to make grace into law, and the Antinomians to make law into grace.
Covenant Theology historically teaches bicovenantalism as opposed to monocovenantalism. Redemptive history is split into two overarching covenantal paradigms: the Covenant of Works and the Covenant of Grace, reflecting the Lutheran contrast of Law (Covenant of Works) and Gospel (Covenant of Grace). While the Puritan and Scottish tradition expressed this teaching succinctly in the Westminster Confession of Faith (cf WCF Chapter VII, Para II), it is not expresseively found in the Confessions and Catechisms of the Continental Reformers due to their creeds and confessions being written early in Reformation history. Yet, a look at for example eminent Dutch Reformed theologian Herman Witsius' magnum opus The Economy of the Covenants Between God and Man  would prove that the Continental Reformed churches also do embrace bicovenantalism, although of course variations between Reformed theologians are to be expected (Compare for example Samuel Rutherford's  understanding of the covenants to Witsius').
A covenant is made up of two contracting parties, with stipulations for the parties involved, and rewards and punishments for the fulfilling of the obligations. Covenants may be unilateral as being more along the lines of ANE (Ancient Near-East) suzerainty treaties, of which God's covenants are similar to . As O. Plamer Robertson defines the biblical idea of covenant when predicated of God, it is a bond-in-blood sovereignly administered . Within the context of a covenant initiated by God, God bonds himself to the other party (i.e men, Adam, Israel etc) by His own free choice and unilaterally lays down the stipulations of the covenant (what they are to do), and the rewards and punishments for their obedience and disobedience respectively for fulfilling these stipulations.
In the context of a covenant therefore, where men under the covenant fulfil the stipulations of the covenant, they are said to have "merited" the rewards promised them in the covenant God made with them. The historic idea of "merit" and the concept of "earning salvation" is set in the context of God's covenants as initiated by Him.
Therefore, historic Covenant Theology talks about men meriting with God on the basis of the covenant. This does not mean that God owes men something for some good they have done, but that rather God owes it to His own integrity as the Covenant God who makes good on what He has promised.
Both the Belgic Confession and the Heidelberg Catechism have a section on the idea of merit, and both of them are quoted to support the attack of the Mono-covenantal Antinomians against the historic view of bicovenantalism. However, is that a proper appeal to the confession and catechism, or rather an improper appeal to them?
Question 63 of the Heidelberg Catechism in situated in the context of salvation; of being right with God. Question 60 asks of us how we are righteous before God, and the only answer that we should give is that we are righteous only because of having faith in Christ. Question 62 asks us why our good works cannot be the whole, or part, of our righteousness before God. The answer in itself damages the case of Mono-Covenantal Antinomianism. It is as follows:
Because, that the righteousness, which can be approved of before the tribunal of God, must be absolutely perfect, (Ga. 3:10, Deut. 27:26) and in all respects conformable to the divine law; and also, that our best works in this life are all imperfect and defiled with sin (Is. 64:6).
It can be seen that question 62 teaches that there IS indeed a righteousness which can be approved before the tribunal of God, which is that of perfect righteousness. As long as a person has perfect righteousness, his righteousness can be approved before God. Of course, that is impossible for fallen men, but that's besides the point here.
Question 63, following question 62, enquires as to whether our good works merit before God. In other words, do our good works count for anything in God's sight such that He would reward us for doing them?
The answer given to the question is an emphatic no. The catechism teaches here that our good works do not earn us anything before God, but rather God rewards us for them due to His grace, not our merits.
The context of this answer however shows us that it is addressed to fallen sinful men who have already violated the works principle in the Covenant of Works (cf Rom. 2:6-11). Postlapsarian men are all born sinners and thus cannot hope to merit anything with God, nevermind the fact that even if they were to do the impossible — to not commit sin plus somehow avoid the Original Guilt of Adam — they still cannot earn the positive righteousness before God necessary to enter heaven, for there is no Covenant of Works made with them.
In the Belgic Confession of Faith, the section whereby the passage is taken from is Article 24 which is entitled the Sanctification of Sinner. Similar to the case of the Heidelberg Catechism, it is addressed to postlapsarian sinners whose only way of salvation is fond in Jesus Christ alone.
Both of these passages proof-text Lk. 17:10 to support their statement, and a look at the passage and verse would show that the case the catechism and confession is making is solid, and in fact the verse is broader in application than either have used them; being applicable across the lapsarian divide. Creatures are obligated to their Creator, and cannot merit anything with Him.
After understanding the teachings of historic Covenant Theology and look at the teachings of Scripture, we perceive immediately that the objections of the Mono-covenantal Antinomians miss the mark altogether. We have said that in Covenant Theology, the idea of "merit" within the context of Covenant is that God does not "owes men something for some good they have done, but that rather God owes it to His own integrity as the Covenant God who makes good on what He has promised". The issue therefore is not, as the distractors would have it, that men obligate God to reward them (an erroneous teaching soundly refuted by Lk. 17:10), but that God obligates Himself to reward them. When this is properly understood, the objection on this ground made by the Mono-covenantal Antinomians are seen to be baseless.
In conclusion, men can "merit" before God only in the framework of a covenant. Specifically, only within the framework of the Covenant of Works can such "meriting" happen, as only the Covenant of Works has a stipulation attached to it for men to fulfil. In the Covenant of Grace however, the stipulation is fulfilled by our represetative head which is Chrst in His humanity. For His own people the elect therefore, the Covenant of Grace does not contain any stipulations or conditions on our part, as our salvation is purely of grace and grace alone.
 Herrman Witsius, The Economy of the Covenants between God and Man – Comprehending A Complete Body of Divinity, trans. William Crookshank (Original printed 1822; Reprinted Kingsburg, CA: den Dulk Christian Foundation, 1990; Distributed Phillipsburg, NJ: P&R Publishing)
 Samuel Rutherford, C. Matthew McMahon (Ed.), , The Covenant of Life Opened (Original 1654; New Lenox, IL, USA: Puritan Publications, 2005)
 See Michael Horton, God of Promise: Introducing Covenant Theology (p. Grand Rapids, MI: Baker Books), pp. 23-28.
 O. Palmer Robertson, The Christ of the Covenants (Phillipsburg, NJ: P&R publishing), p. 15