What does Romans 5:20 mean?

Romans 5:20 addresses a puzzle that naturally arises when reading Paul's argument in this section of Romans: if humanity's problem is sin inherited from Adam, and salvation comes through Christ, then what role does the Mosaic Law play in all of this? Paul answers here that the Law "came in besides" — meaning it entered the story at a later point, alongside or in addition to the main narrative of sin and grace that began with Adam and culminates in Christ. The Law's purpose, Paul says, was "that the trespass might abound." This does not mean the Law caused people to sin more in a moral sense, but rather that it exposed and multiplied the visibility of sin by turning vague wrongdoing into clearly defined transgression against specific commands. Once God gave explicit commandments, violations of those commandments became measurable and undeniable — sin was no longer just a general human condition but a concrete, nameable offense against God's revealed will.

The context here is Paul's larger argument in Romans 5, where he is contrasting Adam and Christ as two representative heads of humanity. Through Adam's one act of disobedience, sin and death spread to all people; through Christ's one act of obedience, righteousness and life become available to all who believe. Paul, writing to the church in Rome — a mixed congregation of Jewish and Gentile believers — is explaining how Christ's saving work compares to and surpasses the devastation caused by Adam's fall. The mention of the Law in verse 20 answers a natural objection: since Paul has been talking about sin entering through