doubt

There could be doubts; a great majority of Muslims might have doubts. Doubts would not make one abandon religion. They are called people of faith because they resist those doubts. Doubts come upon them as well, but Muslims fight it off with their minds and do not accept them. That is the reason why they are called the people of faith. I mean those who resist doubts; those who resist the doubts inspired by the satan and by their own lower-selves are called Muslims.

Just like the prophets, people will judge Hazrat Mahdi (pbuh) as well and they will look at him with suspicion.