Good thread, Hamilcarr
I'm just reading a book entitled "Origins of Christian and Pagan beliefs"
It outlines pagan roots for Christian practices such as the Eucharist. Consuming bread and wine as symbols is part of modern pagan rituals too.
Other things include the requirement for a saviour god. In Pagan mythology, often the god was symbolically slain in order to "save" mankind as part of the year's cyclical vegetation rites. His blood was outpoured for the good of mankind.
Osiris in Egyptian mythology was slain and reassembled (brought back to life by being put back together) - thereafter ascending to a state wherein he met those who died (their underworld was similar in idea to our heaven in reference to it being the place where the dead go to).
The winter solstice (around end of december) often heralded the "birth" of the Sun God because the people's observed the shortest day (sun at his weakest) and then the subsequent longer days (ie. he was reborn) so this is why many gods prior to Jesus were said to have been born around this time.
At around 3000BC, the sun would rise in the constellation of Virgo at the time of the winter solstice - hence "virgin birth" of these gods. Despite some of them not being exactly the same myth (a woman impregnated by god) they still had the commonality of not being "natural human" births - but rather something caused by God in which a mortal woman didn't participate in.
There is much, much more....
Sirona