General resurrection or universal resurrection is the belief in a resurrection of the dead, or resurrection from the dead (Koine: ἀνάστασις [τῶν] νεκρῶν, anastasis [ton] nekron; literally: "standing up again of the dead") by which most or all people who have died would be resurrected (brought back to life). Various forms of this concept can be found in Christian, Islamic, Jewish, Samaritan and Zoroastrian eschatology.
Immortality is the concept of eternal life and permanent resistance to death from natural causes. Some species possess "biological immortality" due to an apparent lack of the Hayflick limit.
From at least the time of the ancient Mesopotamians, there has been a conviction that gods may be physically immortal, and that this is also a state that the gods at times offer humans. In Christianity, the conviction that God may offer physical immortality with the resurrection of the flesh at the end of time has traditionally been at the center of its beliefs. What form an unending human life would take, or whether an immaterial soul exists and possesses immortality, has been a major point of focus of religion, as well as the subject of speculation and debate. In religious contexts, immortality is often stated to be one of the promises of divinities to human beings who perform virtue or follow divine law.