Trying to prove a negative is an informal fallacy.
Now, concerning the Bible. I am an atheist who has read it. Your God (Jesus) did give a message to the seven churches. Also, it was your Jesus Christ who defined what the Church was - - 'Where ever two or more of you are gathered for my namesake, there shall I be in your midst...'
These instructive statements are hardly a representation to advocate the modern idolatry of current traditions surrounding Christmas...
Trying to prove a negative is an informal fallacy.
It is also an informal fallcy to say becuase it cannot be proven, it must be true. Fallacy of accident. You are also not immune to it, sir...