So, in the same way that sin entered the world through one person, and death came through sin, so death spread to all human beings with the result that all sinned.
References for Romans 5:12
Although sin was in the world, since there was no Law, it wasn't taken into account until the Law came.
But death ruled from Adam until Moses, even over those who didn't sin in the same way Adam did—Adam was a type of the one who was coming.
But the free gift of Christ isn't like Adam's failure. If many people died through what one person did wrong, God's grace is multiplied even more for many people with the gift—of the one person Jesus Christ—that comes through grace.