Therefore, what will we say that Abraham, our forefather according to flesh, has found? For if Abraham was declared "righteous" out of deeds, then he has a boast. But rather, not toward God. For what does the Scripture say? "And Abraham believed God and it was counted to him for righteousness." Now to him who labors, wages are not counted as kindness, but rather as obligation. But to him who does not labor, but who believes in the One who declares "righteous" the ungodly, his belief is counted for righteousness. Just as David declares the blessing of the man to whom God counts righteousness without deeds "Blessed is he whose lawlessness was forgiven and whose sins were covered over." "Blessed is a man whose sin the Lord will not count." (Romans 4:1-8)
4:1-2 Therefore, what will we say that Abraham, our forefather according to flesh, has found?… Abraham was the patriarch for the Israelites. It was to Abraham and his seed that God promised blessing. Therefore, if Paul could use Abraham to illustrate his point, it would go a long way in persuading the Jews. So, what did Abraham, the Jews' biological ancestor, discover in terms of justification?
For if Abraham was declared "righteous" out of deeds… Verse 2 is a common form of argumentation called a Conditional Statement. (Also known as an If/Then statement. In formal logic, the if clause of a conditional statement is called apodosis [sometimes antecedent]; the then clause is called protasis [sometimes consequent]. A conditional statement is valid when either the apodosis is affirmed or the protasis is denied. Consider the following example: If it rains, then my car will become wet. If it rains is the apodosis and then my car will become wet is the protasis. According to this statement, I can be sure that if it is, in fact, raining, then it is also true that my automobile is becoming wet. I can also know that if my car is not wet, then it is certainly not raining. It does not work the other way, however: we cannot arrive at truth by denying the apodosis or affirming the protasis. In the example above, if I know that it is not raining, this does not prove that my car is dry. Somebody may have sprayed it with a hose. Conversely, if my car is wet, it does not require rain. I may have just gone through a carwash.)
Confusion exists, however, because the last clause is elliptical; part of the argument is assumed, but not written. The full argument would go like this—If Abraham was justified out of works, then he has a boast. But, Abraham does not have a boast toward God, therefore, Abraham was not justified by works.
3 For what does the Scripture say?… The Bible confirms that Abraham was righteous because of his faith.
4 Now to him who labors… Imagine a neighbor trying to sue you because you did not graciously give him $100? The case would not be given a second glance by any judge. But, if an employer fails to pay the agreed upon salary to his employee, then the worker has grounds for complaint because wages are not paid out of generosity, but out of obligation; they are debts which need to be paid. The point is that if justification comes as a result of an individual's obedience, then it is not a matter of grace, it is a matter of requirement. Justice would require God to justify someone who has kept the Law, but, as we saw in 3:24, justification is a gift given out of God's free grace.
5 But to him who does not labor… A restatement of the theme—for those who lay aside their own efforts and trust in the work of Christ, their belief procures justification.
6-8 Just as David declares the blessing… As the apostle asserted earlier, the Old Testament Scriptures testified to the doctrine of justification by faith. Exhibit A is David, the man after God's own heart, who understood the true blessing of God all too well. After committing adultery and having the husband of his paramour murdered, David had nowhere to turn except the grace of God. The Law was merciless toward adultery and murder; those who were found guilty of such debauchery were to suffer the death penalty. Did David hope to be justified by the Law? No, he appealed to, and hoped in, the kind forgiveness of a gracious God. (In Psalm 51, the wonderful prayer of contrition and repentance, David acknowledged that there was no hope of forgiveness in the Law. He did not go quickly to the altar because there was no sacrifice for these kinds of sins. His only hope was the underserved mercy of God.)
(Romans 3:27-4:8, Extended Paraphrase)
If justification is a gift, then why would anyone brag about his righteousness? There is no place for bragging. For how did he become righteous? By keeping the Law? By doing good deeds? No, he became righteous by obeying the Law of Faith. Because we consider a person to be justified by belief, not by keeping the Law. Or does God's reign only extend to those who have Law—the Jews? Is He not the Lord of the Gentiles also? Yes! He is the Lord of the Gentiles, too. If it is true that God has one providential plan, then He will declare “righteous” the circumcised Jews from faith and the uncircumcised Gentiles by faith. If justification is by faith, then are we saying that the Law is useless? May it never happen! On the contrary, we are showing that the Law accomplished its purpose of teaching the Jews about their sinfulness. What did Abraham, our great ancestor and patriarch, find regarding justification? Because, if he was declared "righteous" because of his deeds, then he would have something to brag about. But, he does not have anything to brag about, therefore, he was not declared "righteous" because of his deeds. This is exactly what the Word of God proclaims, that "Abraham trusted God, and it was counted to him for righteousness." Now, for the one who receives something that he has worked for, his wage is not a gift, but it is a debt. But, for the one who does not work for righteousness, but trusts in the One who declares "righteous" those who are evil, his trust is counted for righteousness. It is just like what David said regarding the blessing of the man to whom God counts righteousness without considering his deeds, "Blessed are those whose lawless acts were forgiven, and whose sins were covered over." "Blessed is the man whose sin the Lord does not count.”