I’m actually surprised at how brief this one turned out to be! (I’m sure you all are as well). Here’s the passage:

12 Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned 13 for sin indeed was in the world before the law was given, but sin is not counted where there is no law. 14 Yet death reigned from Adam to Moses, even over those whose sinning was not like the transgression of Adam, who was a type of the one who was to come. 15 But the free gift is not like the trespass. For if many died through one man’s trespass, much more have the grace of God and the free gift by the grace of that one man Jesus Christ abounded for many. 16 And the free gift is not like the result of that one man’s sin. For the judgment following one trespass brought condemnation, but the free gift following many trespasses brought justification. 17 For if, because of one man’s trespass, death reigned through that one man, much more will those who receive the abundance of grace and the free gift of righteousness reign in life through the one man Jesus Christ. 18 Therefore, as one trespass led to condemnation for all men, so one act of righteousness leads to justification and life for all men. 19 For as by the one man’s disobedience the many were made sinners, so by the one man’s obedience the many will be made righteous. 20 Now the law came in to increase the trespass, but where sin increased, grace abounded all the more, 21 so that, as sin reigned in death, grace also might reign through righteousness leading to eternal life through Jesus Christ our Lord.

Now, follow my thinking here:

5:12  death (not guilt) passes to ALL humans

One man (Adam) = sin entered the world = death

5:15 – the free gift is not like the trespass – Paul sets up a contrast, but he’ll also be making comparisons.

5:15 – If many died . . .

I take this to refer not to physical death, but the second death, which not all will suffer (see earlier posts on that)

. . . grace abounded to many – i.e., the ones not suffering the second death

Take the above to 5:16

5:16 – the one trespass brought condemnation (to many, not all), and so the free gift brought justification (to many, not all)

5:17 – by the one man’s sin, death reigned (not guilt), but that sin brought many under condemnation, and so how much more will those who receive grace (not all will, but many will)

To this point, things extend from my view in a pretty straghtforward way. Then Paul appears to throw a monkey wrench into it.

The toughest verses (for everyone) are the next two, because they use the “all” language on both sides of the equation. BUT (and this is critical) note that the “all” language used in verse 18 CHANGES BACK to the earlier “less than all” (i.e., the “many”) language in v. 19:

18 Therefore, as one trespass led to condemnation for all men, so one act of righteousness leads to justification and life for all men. 19 For as by the one man’s disobedience the many were made sinners, so by the one man’s obedience the many will be made righteous.

My take on vv. 18-19:

1. The one trespass put all humans under the condemnation of death (there’s the “all” note that the condemnation in v. 18 is not specified or defined). It does NOT mean sinfulness since that is brought up in v. 19 in connection with the “many” – NOT in connection with the all.
2. Many of the all who are under the condemnation of death were made sinners (here’s v. 19 and Paul’s “many” noting that Paul goes back to “many” language).

So that:

The one act of Adam that affected all actually led to a subset of many. All were put under the curse of death and, theoretically, all would sin; not all do, though, because they don’t all get to live. The many who do sin are then rightly called sinners.

* IN THEORY, THEN, the “all condition” COULD produce the same outcome for ALL, but the reality is that only MANY will “partake.”

3. The one man’s act of righteousness (here’s the Jesus part of v. 18) leads to justification and life for all humanity. How to avoid universalism here? (and it’s important since universalism is denied elsewhere in Romans 5 and many other places, Pauline and not). I think there are ways to parse this, using my view of Romans 5:12 as a starting point.

a. On one hand, the “life” part is easy, since it could refer to eternal life, which is actually shared by all (unless there is annihilation), the unsaved and the saved. But that’s a bit forced and doesn’t address the justification part. You’d have to redefine justification, which is also self-serving. Better . . .
b. One could simply apply what was said about the first Adam:

The one act of Jesus affects all IN THEORY but actually leads to a subset of many. All could have eternal life and justification, but not all do. Why take it this way? Because it resolves what looks like a contradiction in Paul. In verse 18 Paul says what Jesus did “leads to justification and life for all humanity, but then he turns around and limits it (creates a subset) in the next verse: “so by the one man’s obedience the many will be made righteous.” My proposal has Paul make sense here and not appear schizophrenic.

*IN THEORY, THEN, the “all condition” COULD produce the same outcome for ALL, but the reality is that only MANY will “partake.”

The main contrastive point in all this, of course, is that of death vs. life being the outcome of what the two Adams did.