Is it possible to prove the existence of Imam Mahdi among people, according to Islamic Hadiths?

Shia believes that Imam Mahdi was born in the year of 869 A.D (255 A.H) in Samara and went into the hiding for a wisdom that Allah considered. He is a promised man that Allah has preserved for the benefit of mankind to save them from oppression and degradation. The promise of such a man is mentioned in previous holy books; however apart from the viewpoint that believes he is alive know and that his name is Mahdi, other religions fail to believe so. Sunnis mostly believe that he has not been born yet.

Shia for his claim refers to some groups of Islamic narrations that are profusely mentioned in Shia and Sunni sources. If we do not interpret these narrations with what the Shia believes we have no other way but to say that these narrations are meaningless since there would remain no other acceptable meaning for them.

Some of these narrations are so strong and healthy that their chain of transmitters and the books containing them are not questionable at all. They are so clear and numerous that the scholars believe they have reached to the level of certainty. Surprising enough, many of these narrations exist in Sunni sources.

These narrations are just suited with what the Shia believes and no other famous doctrine can be in agreement with the content of them. In following, we refer to a group of these narrations.
Some of these Hadiths are as follows: the 
Hadith “the Death of Ignorance”, 
Hadith “the Twelve Caliphs”, and Hadith al-Thaqalain (Two precious Things) 
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