It is almost Christmas which means that cable TV channels everywhere are gearing up programs to tell us why everything Christians believe about Christmas is a big fat lie. However, much of what they present is not grounded in fact but conjecture. But first, a movie!
Now, this is a big topic to tackle and I just do not have the time to cover every angle. Suffice it to say, there was actually a movement in Western Europe in the 1800's whose whole point was to undermine Christianity. Back then it was hard to check claims against scholarly research and works. Unfortunately, in today's world where it would be easy to do what we get is just a regurgitation of these ideas even though they have been debunked over and over again. Case in point, a common picture floating around on the internet right now is this:
At the heart of all this is the Christ Myth Theory. Wikipedia has a pretty good primer on this.
It should be noted that Bart Ehrman is one of the biggest critics of Christianity. And even he is calling cow manure on this. YouTube has some pretty decent videos that are well sourced, so I will let them do the talking on this.
I think you are getting the point by now. The same above is also true for Attis. Many of the so called "parallels" came after Christianity had been established.
And, finally, because humor is important, one final Lutheran Satire video. I hope you have a very merry and joyous Christmas!