Mr. Khamenei; the leader said:

The difference between us (Shia) with others the other Islamic and non-Islamic sects or others , is that we know this precious and supreme person;
We know his name, birth date, his precious father and mother and his ancestors, and what happened to him. But the others don’t know these. That is why Shia’s recourses, are livelier, more fervent, more meaningful and more oriented.

All the Muslims believe in the origin of Messianic. but their information is imperfect in the main part, which is knowledge of the savior (hgr).
But Shia has documentary information about the savior (hgr)`s name, family tree, characters, and his date of birthday .

“A Part of the supreme leader`s speeches “, (۱/۷۱۹۹۶) and (9/2/2005)