On Mythras, Myth, the Virgin Birth and December 25th

There is an interesting post on this topic over at "God is for Suckers." This is the conclusion:
So, the short version is – there is no evidence that Christianity borrowed from Mithraism, nor is there any vice versa. I am convinced that Theodosius I’s implementation and enforcement of the Nicene religion led to the destruction of a great many documents and monuments that would have given us substantial proofs one way or another, but alas I cannot prove it. As a talking point, it’s a fair illustration of not only how parallels occur (or are borrowed, or pinched, or whatnot), but also how incredibly sketchy historical veracity becomes when the Christians took over. Outside of that, it’s not the sort of factoid that will slap the reader into some sort of admission. Then again, as we all know, facts are for the pragmatist and the realist, not the religionist.


What think ye?