. . who's given name translates to something like "Savior" in it's original form and language.
Christianity is a pastiche of what was going around in its day so there's no reason Jesus couldn't be a pastiche as well. In any case there were groups describing themselves as "Christians" for many years before birth of Jesus "the Christ".
Again, at the time it wouldn't have been particularly important whether he was a real person or not - people just weren't so literal as they are now.