If Abraham was justified by works, what would that have meant according to Romans 4:2?
If Abraham were justified by works, it would mean his justification rested on what he could accomplish or earn by his own effort. Romans 4:2 indicates that would give him reason to glory or brag, but never before God, since no one can boast before God.
Les explains that being justified by works would mean justification by what Abraham could accomplish or by what he had earned. In that case, Abraham would have reason to glory or brag, but never before God. No one is ever going to brag to God, "Look what I've done," and God will never allow it. Not even with a man like Abraham would He permit him to say, "God, do you realize all that I've done for you?" Abraham could not do that. In fact, while he was waiting, he failed miserably and fell flat on his face. Earlier context also stresses that even Abraham, the great man of faith, was faith plus nothing; it was not that he had accomplished so much or was such a great individual.
For if Abraham were justified by works, he hath whereof to glory; but not before God.