I have never understood why some atheists want Jesus to be a fiction. It appears to me that a historical Jesus should make no difference to atheist beliefs.
God doesn’t exist.
If Jesus was a real historical figure then …
Jesus and some people made up the events described in the New Testament.
If Jesus was purely fictional figure then …
some people made up the events described in the NT.
It’s the slippery slope syndrome. Once someone from “the other side” is willing to concede something that our side believes we feel all the more confident that eventually she’ll concede…more? And when someone from our side concedes something the other side believes he usually catches hell.
So hardly anyone will concede hardly anything.
And because this is not something that can be [or has been] nailed down empirically, it becomes all the more about human psychology than “the truth”. In the realm of religion it’s that we believe something is true that seems to count more than what we believe is true.