Joseph Atwill is about to present, for the first time in the United Kingdom, his thesis that Christianity was an invention of Flavian-era Roman elites as a means to tame the nascent threat of rebellion coming out of Judea and subvert that movement into a state-sponsored cult whose purpose is to continually apologize and propagandize for the obedience of the people to the state- and thus to its head, the Emperor. I have no opinion, at this time, regarding whether or not this thesis is valid. What I want to do is give you some idea as to where he's coming from, and let you decide for yourselves if this is a valid inquiry or not. The embedded playlist includes recent and older videos and radio recordings uploaded to YouTube. The full video production is embedded below that playlist.
All that's missing for your consideration is the book itself, and the sources used to make that and the film version of it. Have at it.