What part of our salvation experience do very few people understand?
Very few understand the role of old Adam in salvation: we are not sinners because we break the law; we break the law because we are sinners by birth from Adam. This inherited sinful nature is a foundational part of the salvation experience that many are unaware of.
Les explains that in Romans 4 he is dealing with justification by faith plus nothing, and he notes that very, very few have a real understanding of what Paul is trying to teach in these chapters. He then says that when they get to Romans chapter 6, they will take a good, hard look at old Adam, and that this is a part of our salvation experience very few people are aware of. He puts it on the board: we are not sinners because we've broken the law; we break the law because we're sinners, and we're sinners by virtue of being born from Adam.