For while we were still weak, at the right time Christ died for the ungodly. For one will scarcely die for a righteous person—though perhaps for a good person one would dare even to die— but God shows his love for us in that while we were still sinners, Christ died for us. Since, therefore, we have now been justified by his blood, much more shall we be saved by him from the wrath of God. For if while we were enemies we were reconciled to God by the death of his Son, much more, now that we are reconciled, shall we be saved by his life. More than that, we also rejoice in God through our Lord Jesus Christ, through whom we have now received reconciliation.
This reads like a story of “our” conversion. It is as if Jesus’ death was the time that we came to faith and were justified.
But many had faith before Jesus died and many did not come to faith until long after. Some were, like Abraham, already justified in some way. Others were still under the wrath of God long after Jesus died.
So Paul is somehow personifying the human race in history and regarding Jesus’ death as an objective verdict on us all.
He likewise personifies the nation of Israel as a single Jew whom he questions in Romans 3.
And this means that he could identify with Israel in Romans 7. He has already set the precedent for this sort of rhetorical strategy.