Again, all of these people (Richard included, whom I'm sure will be on the Black Rock) are superstitious being believing in the specialness implied by these supernatural circumstances.
Richard thinks Locke is special because:
A) in 1954, Locke told him "Jacob sent me" and then he disappeared before his eyes
B) sure as he was told, Locke was born in 1956 and Richard went to see him
C) despite being tested over the years by Richard and Locke's having failed his tests, in 1977, Jack tells Richard that Locke is special. Why does Jack think Locke is special? Because he showed up in 2007 and knew his dead father's name was Christian. Jack finally gave in to all of Locke's self-belief.
Locke is special only in that he was chosen by Jacob as a "candidate" (to alter the course of history / be a leader of the Others). It even looks like Jacob brought Locke back to life after dying from falling out of the skyscraper window. But, that's not Locke's specialness, that's being the recipient of Jacob's special powers.