AquaScorpio, there are references from authors of ancient Greece and Rome in the book Nexus cites: The Jesus Mysteries. See also Tom Harpur, The Pagan Christ. The grand-daddy of these sorts of books was James Frazier, The Golden Bough. Their bibliographies will guide you to the original classical sources.
The writings of the early church fathers indicate that they were well aware that Christianity had pagan as well as Jewish roots, but they explained them away to the new Christians by stating that the devil had devised them to lead the faithful astray. Note also how many early saints had the names of pagan deities. Brigid was a Celtic goddess before she became a patron saint of Ireland.
Classical studies scholars have also shown that Jesus couldn't have been born on Christmas day. The Romans conducted their censuses in the summer. Christmas eve is off from the winter solstice by about 3 days because it was hard for people without accurate or consistent calendars to pinpoint the soilstice exactly; but by 3 days after the solstice, one could see that the daylight lasted a few minutes longer and that the sun had moved slightly north.
Obviously the pagan trappings of yule logs, mistletoe, Christmas trees, &c are with us to this day.
Do Christian churches want the faithful to know this? Not likely.
Today we call planets by the names of gods that come down through times when people believed in them.
My personal belief is that Jesus was a real person, but a reformer who preached a radical code of ethics-- that hardly anyone can live by. The miracles have much older pagan antecedants. The Virgin birth, for example, sounds a lot like the god Zeus/Jupiter mating with human women who gave birth to the founder of various ethnic groups. The death and resurrection is precisely the agricultural ritual of many societies. Jesus, after all, was a god whose body was bread and blood was wine.