Charles Ellicott Commentary Romans 5:16

"And not as through one that sinned, [so] is the gift: for the judgment [came] of one unto condemnation, but the free gift [came] of many trespasses unto justification." — Romans 5:16 (ASV)

The judgment was by one.—The judgment, verdict, or sentence from a single case ends in, or in other words takes the form of, condemnation; whereas, on the other hand, the free gift, starting from or prompted by many sins, ends in, or takes the form of, justification. In the former of these cases the verdict is “Guilty,” while in the other case it (or, rather, the free act of grace which takes its place) is a verdict of acquittal.