Him to another poster---"You're the lunatic who insisted that there is no proof Christianity existed before 300 AD"
Undoubtedly, it did exist before then. CHRIST was the one who started it. There were some big councils and decisions made though around 300 AD and probably where modern Christianity began to take shape.
I, of course, argue that Christ's existence is a matter of historical fact, not belief. What is a matter of belief is whether we believe that Christ is who He claimed to be.