In two thousand years does any one have the name of someone who has definitely been 'saved' through calling on Jesus?
As a matter of fact I know many, including myself who have called upon Christ for salvation and received the gift of the Holy Ghost.
Christianity is something to believe and someone to receive. The evidence of salvation is the transformation of a life that only the person transformed can know and give testimony to by a change in behaviour.... though skeptics without knowing the person before or after may choose to deride.