Why do Catholics believe that the dead can be saved when the Bible states otherwise?

This question is directed to followers of the Catholic Faith, why do they believe that the dead can still be saved if we intercede for them when scripture explicity states that it is appointed for men to live once after which death and judgment follow. *Hebrews 9:27* >And just as it is appointed for man to die once, and after that comes judgment I interpret the verse above to mean that after we die then there is nothing we can do to either glorify or provoke God and that is why we await judgment for works done while in the body. The story of the rich man and Lazarus also shows that the dead can't be saved because the rich man would have applauded to Abraham to intercede for him to enter into life but that didn't happen, the brothers of the rich man were the ones who were still in the world and their hearts were hardened against the prophets and the oracles, which mean that you can still be saved while still in the world and not when you have departed from it. Why do Catholics believe so?