What does Romans 5:17 mean?
"Death reigned" (Romans 5:14). That was the result of Adam's sin. Sin always brings death. Death became king. It ruled the lives of every person born from Adam.By contrast, Paul now writes, those who receive the abundance of God's grace and the free gift of righteousness will themselves reign in life through Jesus. In other words, receiving God's justification by placing our faith in Christ not only frees us from the kingdom of death, it allows us to rule in the kingdom of life alongside Jesus, as the very children of God. Some translations add the word "will" before reign, since the Greek word here—basileusousin—is in the future tense. This verse very likely points to a future time when Christ's kingdom will be fully established on earth, although our status as His co-heirs is already established (Romans 8:17).
It's essential to notice, however, that Paul has added a qualifier in this verse: This freedom from death and life in Christ is available only through Jesus and only to those who "receive" the abundance of God's grace. Not everyone escapes death's reign, because not everyone receives, by faith, God's gift of life (John 1:12).