Xianity, as far as I know, is the same as Christianity.
Christ is more of a trace of personality than a man that actually existed. He's the harbinger of the teachings of the supreme, and after his crucifixion, he's the accuser, the one who'll judge and punish when needed. In other words, he's the good and the evil, he's Lucifer (as Jesus refers to himself) and Satan, the builder and the destroyer. That's what we all are and everything is, the duality. As a friend of mine use to say there's only 2 ways to learn things - by love or pain; humankind chose not to learn by love when they had the chance, now learn by pain.
I hadn't noticed that FFTGGOG lyrics had been mentioned, but as with No More Lies, Steve questions Christ's deeds and his knowledge - how far a man would go to open people's eyes and make sacrifices to see a higher moral of brotherhood and goodness among mankind? That's a question myself, which don't like organized religion, but like to read about all the primal and essential religions there are, pose on how much suffering we go through in life to make those we know and love better beings. How much of the hystorical Christ there in us? That's what I meant about concept of Christ. Anyone can be Christ 'cos it's a point of view, a vow one make to himself and as a compromise with their fellow men. That's the essential christian belief.