This is the prayer of the tax collector (Luke 18:13), “God be merciful to me a sinner.” Jesus says that the one who prays that prayer goes home justified, not on the basis of the quality of his prayer nor on the basis of anything done by him or wrought in him (WCF 11) but only for the sake of Christ’s righteousness credited (imputed) to him and received through faith alone (sola fide).
One of the most persistent temptations Christians face is that of turning the covenant of grace into a covenant of works. As we pray we must always be reminded that we, who trust in Jesus Christ as our substitute and Mediator, are not in a covenant of works but in a covenant of grace. You know what a covenant of works is, even if you have never read the term before. The colorful metaphor used by our Lord himself in the fifth petition, “debts” (ὀφειλήματα in Matt 6:12) or “owing” (ὀφείλοντι in Luke 11:4) drives home the point quite powerfully.
Borrowing and repaying money is a covenant of works. There was a time when debtors who could or would not repay a loan faced not only repayment but prison for failure to repay. Perhaps you have never had dealings with debt collectors. It is not pretty and it is not meant to be. Collectors intentionally make things as miserable as they can in order to encourage debtors to pay up. Many years ago I a friend of mine, who worked in the debt collection business, warned me never to run afoul of them because, as he said, “we do not hire nice people to collect debts.” He was not kidding.
When a bank loans you money, they expect to be repaid. If you fail to pay the mortgage, eventually a sheriff’s deputy will appear at your house. You will be evicted and the house will be repossessed and sold to repay the mortgage. If you fail to make the payments on your car loan, the “repo” man will take your car back. Pleading will change nothing. They have heard it all. They do not get paid for being merciful and gracious. They get paid for recovering the house or the car. That is a covenant of works.
Christians, i.e., those who have true faith, are not in a covenant of works because Jesus Christ has fulfilled the covenant of works for them. Those are gospel words: “for me.” The Pelagian says, “I have done.” The Romanist and the Arminian says, “by grace (and my free cooperation with grace) I have done.” The confessional, evangelical Protestant says “Christ has done for me.” Paul says:
Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned…Therefore, as one trespass led to condemnation for all men, so one act of righteousness leads to justification and life for all men. For as by the one man’s disobedience the many were made sinners, so by the one man’s obedience the many will be made righteous (Rom 5:12, 18–19; ESV)
God offered Adam eternal life, communion with him, and glory on the condition that he obeyed the moral law summarized by the command not to eat of the tree of the knowledge of good and evil. Adam disobeyed God’s moral law and plunged himself and all humanity in corruption and death (Eph 2:1–4). As Paul says in Romans 5, sin brings death. When he says “all have sinned and fall short of the glory of God” (Rom 3:23) he is thinking of Adam and of us in Adam. We need another federal head, another representative, a substitute. Jesus the Messiah is that substitute for all who believe.
As the principal lies unpaid and the interest on the debt continues to compound, the debtors misery grows daily. Every debtor wishes that someone, somehow would come and help. If only the debt could be wiped out. For those who believe, God imputes our debts, our sins, to Jesus. This is the teaching of our Lord himself (Luke 22:37). Our translators do not always help us because they use a variety of English words for the same Greek word (λογίζομαι), “to impute” or “to reckon.” This is the language of accounting or banking and this is why the metaphor debt is so apt. By the fall we all became debtors to God and divine justice is such that he must collect.