What we can be almost absolutely sure of, is that whatever the historical basis for Jesus, that person or persons would not even get close to recognising the version of Jesus that the vast majority of Christians believe in.
You'd believe if you just opened your heart" is a terrible argument for religion. It's basically saying, "If you bias yourself enough, you can convince yourself that this is true." If religion were true, people wouldn't need faith to believe it -- it would be supported by good evidence.
