Christianity, itself, has "pagan" origins. The story of Jesus is merely a "re-hashing" - a "re-cycling", or reinterpretation - of the myth of Horus and other "pagan" narratives. Does anybody recall Jesus' miracle of "transforming" water into wine in the second chapter of the gospel of John? That was already "old hat" in that era. It was a common practice among the priests of Dionysus. In fact, Jesus is often referred to as "Dionysus in new clothing."
And what of the notion of the "virgin birth"? Again, this is merely an old "pagan" idea. The commonly quoted scriptue at Isaiah 7:14 - "a virgin shall conceive, and bear a son..." - is, in fact a mistranslation. As Strong'sConcordance points out, the term in question "can refer merely to the unmarried status of the one so described. The child immediately in view was the son of the prophet and his wife who (cf Isa. 8:3) who served as a sign to Ahaz that his enemies would be defeated by God." In the Hebrew scriptures, there is no indication whatsoever of an expected or awaited "virgin birth." Why would there be, when the Jews were supposed to be hostile to any such pagan notion? The very thought of a virgin birth is utterly risible and ludicrous. But it is also pagan. In the pagan tradition, gods born of a virgin were a dime a dozen. In fact, a virgin birth was almost a required aspect of a pagan god's "pedigree."
Everything aboutthe Jesus myth - from his dying and reviving, to his halo - is merely a "re-working" of pagan narratives. And don't forget the wandering "star" that greeted his birth. Yet another pagan myth grafted on to the narrative.