Basically, if someone’s birth, life and living is proved; then his death requires proof and not his living. Thus, when we meet someone we never ask him, “why are you still alive? “ To be alive after birth is a rational principle. If we hear the death of someone, we immeadiately inquire about the reason of this death – no matter whether he or she is young or old, healthy or sick; we always wish to know the cause of his or her death. In other words, death requires a cause.
However, this principle varies in various instances depending upon its dimensions and length of time. For example, the existence of one stone may continue for hundreds of years while that of a rose flower may last for few weeks only.
About Hazrat Mahdi (a.t.f.s.), the matter concerns special divine confirmation, and Hazrat’s extraordinary power possessed by divine permission. Hazrat enjoys loft power and strenght and in this regard numerous glad tidings and indications have come down like, “He bears resemblance to prophet Noah in longevity. Reliable traditions about the birth, life and visitation of numerous people with Imam-e-Zamam (a.t.f.s.) proves that he is alive and is endowed with powers far above the human power.
So reason deduces that he is alive unless his death is proved by strong evidences and who can dare make such a claim!? On the contrary, his life, existance and protection of the Islamic community and the Shias, during major concealment, is as clear as broad daylight.
For the sake of finalizing the argument, the All-Knowing and Wise Allah has shown this luminous moon to a few special, pure and sincere followers right from the time of Hazrat’s birth till today.