I don't really think the existence of Jesus is that important. You basically have two options.
A. Jesus is entirely fictional, all the miracles associated with him are imaginary because he is imaginary
B. Jesus is a highly fictionalized account of a real person, all the miracles associated with him are imaginary because he is highly fictionalized.
To me there isn't a significant enough difference between a highly fictionalized person 2000 years dead and an entirely fictionalized person made up 1940 years ago to really concern myself with.
A. Jesus is entirely fictional, all the miracles associated with him are imaginary because he is imaginary
B. Jesus is a highly fictionalized account of a real person, all the miracles associated with him are imaginary because he is highly fictionalized.
To me there isn't a significant enough difference between a highly fictionalized person 2000 years dead and an entirely fictionalized person made up 1940 years ago to really concern myself with.