It means God had power over death and the grave. The resurrection of life happens when Jesus comes for his people. Death is just a sleep for the saved. There is no comprehension of time, it's like an instant because there is no knowledge or feelings, etc during death. When Jesus resurrected lazarus, he had been dead 4 days, however there is no commentary of lazarus taking about being in heaven those 4 days and then beamed back to earth, or in hell either because hell isn't even burning yet. The resurrection of damnation is for the lost, and they are reserved and will burn up and be destroyed in hell fire.