I know this is very tough to grasp but the text that Christians refer to is the Bible. Therefore a Christian follows the teachings of the Bible. This is no diff than a Muslim or Jewish person would do for their religious text. You do realize this, correct?
I'm not sure what your point is..? Yes, christians refer to the bible. Then what? It's still an old relic with a bunch of fairy tales in it, and whatever historical correctness it might have had is long gone, filtered out by numerous manipulations and translations.
"Virgin" was most likely a mistranslation of "young girl". Jesus was almost certainly not crucified on a cross, or a latin T as one might call it. In fact, that sort of contraption was extremely rarely used by the romans. More likely candidates are in the shape of an X or our version of T or just a simple horizontal bar nailed to a wall that were a lot more commonly used. There are no historical documents that gives us any information to what sort of device he was crucified on.... except for the bible which can not for obvious reasons be trusted. But I'm sure you knew this, right?