Gospel Guidebook: Getting and Keeping It Right 
More Objections Answered regarding Romans 4
This article supplements and partly overlaps two other articles of mine that deal with Romans 4.
Hebrews 11:8-9 and Imputed Righteousness
Romans 4:17-22 and the Demonstration of Abraham's Faith
Opponents of justification by the imputation of Christ's righteousness to the ungodly have tried in various ways to explain away the plain words of Romans 4, especially verses 3 and 5, by interpreting the word "faith" to include "faithful living" and "commitment." However, in Romans 4:2, Paul draws our attention to the "faithful living" of Abraham, and says that those acts of faithfulness, though certainly worthy of praise before men, gained him no standing with God.
In Isaiah 51:2, we learn that God had exclusively called Abraham, blessed him, and multiplied him, resulting in the faith and obedience we read of in Hebrews 11:8-9. All of this happened before Genesis 15:6 where we are first told that Abraham's faith was reckoned to him for righteousness. Romans 4:2 is significant because it tells us that these works of Abraham, including the faith and obedience mentioned in Hebrews 11:8-9, did not contribute to his justification by faith. This is why Paul carefully positions the content of Romans 4:2 directly before speaking of Abraham's justification by faith in Romans 4:3. He was essentially preemptively refuting the very objection that so many opponents of justification by imputed righteousness are trusting in. Continuing on, the Apostle Paul insists that it was "ungodly" Abraham (Romans 4:5, cf. Joshua 24:2-3) who was justified apart from works (including the "God-produced works" of Hebrews 11:8-9, which are just a subset of works), on the basis of believing God with respect to the gospel that was preached to him beforehand concerning Christ coming through his seed line (Galatians 3:6-8, 3:16, John 8:56).
Opponents of imputation of Christ's righteousness often complain that such a theology creates nothing more than a "legal fiction." But such a complaint could equally apply to the "forgiveness of sins" (Romans 4:7-8), the "imputation of our sin to Christ" (2 Corinthians 5:21), and our resurrection with Christ where we are currently seated with Him in the heavenlies and hidden with Him in God (Ephesians 2:5-6, Colossians 3:3), all of which are positional and forensic (i.e., what our opponents call a "legal fiction"). The Apostle Paul himself carefully connects justification with the "forgiveness of sins" in Romans 4, so when our opponents complain about "legal fiction," they are really complaining against the Apostle Paul.
In addition to the above, opponents of imputation of Christ's righteousness have tried to read Romans 4 through the lens of Psalm 32:5-6 where David speaks of confession of sins and contrition as being the prayer of all "godly" people. The Apostle Paul does indeed quote Psalm 32:1-2, but the context of Romans 4 shows that the Apostle Paul was careful to exclude Psalm 32:5-6 from his argumentation. In particular, whereas David speaks of the "godly man" in Psalm 32:6, Paul is specifically speaking of the "ungodly man" in Romans 4:5. Again, it is as if Paul was explicitly and preemptively refuting any possible objection to his argumentation. It is also important to note that David himself carefully separates the content of Psalm 32:1-2 from the rest of Psalm 32. In the former, he speaks generally of "the man" in the third person, but then shifts to his own personal experience, using the first person pronoun "I," throughout the rest of the Psalm. In light of this, it is not wise to interpret Romans 4 through the lens of Psalm 32:5-6, considering the effort Paul makes to prevent this very interpretation and David's own careful use of third and first person pronouns.
Therefore, based on Paul's argument in Romans 4:1-8, we see that justification by impartation (i.e., "the gospel is sanctification") is impossible. People are not justified because of what Christ does in them to change and transform them into righteous people. Rather, God justifies "the ungodly" as "being without strength," as "being sinners," as "being enemies," and as "being dead in trespasses" (all present participles) (Romans 4:5, 5:6, 5:8, 5:10, and Ephesians 2:5). These "ungodly" ones are the "blessed" ones "unto whom God imputeth righteousness without works" (Romans 4:6). These "ungodly" ones are the "blessed" ones "whose iniquities are forgiven, and whose sins are covered, and to whom the Lord will not impute sin" (Romans 4:7-8).