Criteria of Choosing Prophets and Imams from Hadith Perspective

One of the important questions in the discussion of prophethood is that why, among all men, only special persons are chosen as prophet and are given the status of infallibility? If it is for their merits how did they obtain these merits? As Shia believes that they were infallible from the very beginning, and some of them were chosen as prophet in the very childhood, if it is a gift bestowed upon by Allah why Allah deprives others of this gift and in this case, how is Allah's wisdom and justice is justified? Utilizing hadith and principles of theology, the author of the present paper tries to answer the above mentioned questions.