I ask because many seem to claim that having a path to human salvation of some kind, defined pretty broadly, is something that pretty much all major religions in the world today have, whether it is Buddhist enlightenment or Heaven in Christianity. However, did Roman and Greek paganism have any sort of widespread doctrine or belief about salvation after this life?
There were cults that offered something of an afterlife but we generally don't know much about them as they were mystery cults who kept their doctrines hidden and history has not preserved them. I can think of the Eleusinian mysteries and the cult of Mithras in particular. There's a lot of interpretation on the beliefs of the latter based on the artwork that we have.