You mean Romans 5.20. Paul's point is that the Law alerts us to our sin so much that it's as if we're sinning with every breath we take. But the grace of God is greater than all our sin, and God will never fail to bring eternal life to one who is in Christ. Sin cannot hold a candle to grace.
Notice Paul uses the verb "was added." The Law doesn't create sin or cause sin, though it does provoke it. There's nothing like a rule to motivate people to break it. But it came into this state of affairs between Adam and Christ, and it shows in graphic ways man's desperate need for God's salvation by grace through faith.
Manfred Brauch, in "Hard Sayings of Paul," writes,
"On first reading, this seems to suggest that the purpose of the Law was to make people worse. But this is against the teachings of Scripture, where God is drawing all people to Himself and where the Law is a gift.
"In this section (vv. 12-21), Paul is contrasting the devastating consequences of sin and the magnificence of salvation. All humans, regardless of whether they had the Law or not, are part of corporate humanity separated from God and His good purposes (vv. 13-14).
"This verse, in the context, cannot mean that God intended to increase sin. Paul has already shown both sin and death to be universal realities. It cannot increase beyond this. Thus, the meaning of the passage must be that the Law was given to “increase the awareness, the consciousness of sin” (Rom. 3.20; 7.7-8; Gal. 3.19). The Law revealed the destructive, devastating nature of sin against the good intentions of God. In light of both the Law and God’s grace revealed in Christ (5.20-21), human sin is exposed and revealed to our consciousness in all its magnitude."
> It'd be interesting to know if those words imply anything different in the original Hebrew.
The Hebrew term is simply
tov: good. Dr. John Walton, in "The Lost World of Genesis One," argues convincingly that Gn. 1 is about how God ordered the universe to function, not about its material manufacture. (He's not arguing that God didn't create the cosmos, but only that's not what Gn. 1 is about.) And if the text is about function and order, then "good" needs to be interpreted not as "created good," but rather "functioning 'good'." When God declares that it is good, He is affirming that He has ordered the cosmos to function well (light and dark alternate in sequence, the Earth brings forth vegetation, the sun and moon set the seasons, humans rule the Earth in His stead), not that it is a morally perfect place (where good = righteous).
> I still wonder how one reconciles the idea of God creating a universe with mass death only for that to be the ultimate enemy to be destroyed.
You know that cosmologically and biologically speaking, death is regenerative, not a cessation. Death is a necessary part of a process of bringing forth life. Death in the ecosystems of Earth is essential to the processes of life. Spiritually speaking, death is an enemy.
I attended a conference about 5 yrs ago. One of the lectures I attended spoke to this issue somewhat. The lecturer, William Horst, said,
"Paul has two distinct senses of death in mind between Romans 5 and 1 Corinthians 15. We are not to confuse the two or think he is speaking the same in both chapters. Paul’s letters are not systematic theological treatises. They are letters to two different communities. He construes creation differently in each text, and his cosmological emphases differ between the two books.
"1 Corinthians 15: death = physical death as an aspect of how humans were made in the first place. Mortality is a feature of how humans are built. Death is because of our corruptible bodies like Adam’s. Death is an aspect of creation that needs to be brought under God’s dominion. Paul associates Adam with corporal morality.
"Romans 5: Death is not morally neutral. Death metaphorically involves a life characterized by bondage (an inclination) to sin. Sin operates through members of the body. Death here is not the expiration of the body, but rather moral corruption. Death is a metaphor for moral bondage which translates to all humanity."