In this passage, Paul lays out a divine history according to which the sin of Adam ("original sin") corrupted all of Adam's descendants down to the time of Jesus's death, a death which made possible the removal of that sin. (I stress "possible" because not everyone is eligible for salvation. What is required for salvation?)
In what way did Moses play a role in Paul's divine history? How is this divine history different from the divine history as understood by the Pharisees?