The issue is not that the story had to start from something...this issue is that the story, as given, is not supported by history...
The story, in various forms, had been told for centuries before the alleged life of Christ...yet the early Christians attribute all of these qualities and characteristics to this man called Jesus, thus creating the myth, and then they do everything possible, including falsifying history, to support that myth...even today, there are hundreds of websites that cite the same information as the one that The Philosopher posted, but they are all based on falsehoods...they say this person, or that person wrote about Jesus, when in fact that is an outright lie...
If it were true, that there have been contemporaneous accounts of the life of Jesus, then there could be no argument...but because the Christian apologists have no supporting evidence, they are forced to spread falsehoods...
So, if they are spreading untruths concerning the historicity of Jesus, then why should anybody believe anything else that's written in the Bible as having actually occurred?
And if the Bible is just a haphazard collection of folk myths, then what power can it truly have over the hearts and minds of the billions who profess their faith?
And if the Bible is a fallacy, what then does that say for authenticity of the Quran?
And if the Torah, Bible and Quran are false, what reason then do we have to kill each other?