No, but people from all nations will. In Romans 5:15–19 Paul speaks liberally about the many
or all
for the purpose of not making any distinction between Jew and Greek. His liberal use of these words have caused many to question whether he is not advocating some form of universal redemption here in which faith in Christ then becomes irrelevant for salvation. However, such a question misses the whole point that Paul is making here. He is not attempting to answer the question of whether there are many individuals who will be saved, but he is writing in terms of the relationship between Israel and the nations. Does the law not stand between the Jews with their service of reconciliation on the one hand, and the Gentiles who have no part in the dispensation of Moses on the other hand? In other words, is the death of Jesus in Jerusalem not simply a Jewish historical event? It is against this background that Paul writes about all
people without distinction, not all without exception. The unity of all people in Adam surpasses the special bond that the Jews have with Moses (cf. Rapinchuk1). In that time, this was a rather unexpected approach for a Jew like Paul. Is he forgetting the intervention of Moses and the law? Of course, Paul had already precluded such a conclusion in Romans 5:13–14.2
18 Therefore, as one trespass led to condemnation for all men, so one act of righteousness leads to justification and life for all men.