> I don't understand why the truth about Jesus
> the man could possibly matter to the God-
> Science debate. That is, unless there are
> scientists who take seriously the idea that
> Jesus was a god rather than an ordinary man
> (ordinary in the biological sense). That Jesus
> was not God is, in my understanding, a logical
Although the present focus is on the existence of a community called Nazareth around 0 A.D. because it's an easier fact to prove or disprove than what some ancient carpenter might have said or done, the real goal is to establish the vast superiority of experimentally / mathematically / logically based science as a means to knowledge compared to faith-based superstitious religion.
I'm willing to concede the existence of a man named Jesus, born of Mary and some human father, who was raised as the son of a carpenter, who taught some pretty good ideas to the Jewish communities he visited and was unfairly crucified, and caused the formation of one of the major religions of today, IF the evidence supports that notion. I'm certainly not willing to accept His miracles or His Godhood.
From an atheist's point of view it doesn't matter whether Jesus really existed or not, just whether what He supposedly said and did was true.
However, if Nazareth can be shown to be a fabrication then it brings to clearer focus the important differences between science and religion. Science is a powerful tool to distinguish fact from fiction. Religion is an unreliable source of knowledge, promoted throughout history primiraly by superstitious, scientific - illiterates.
Even the most basic of Christian beliefs (that Jesus really lived) could be a lie. If it is a lie, then EVERYTHING else taught by Christians that violates scientific knowledge could also be lies. Only those ideas confirmable by modern scientists without respect to one's religion (like the importance of being kind to each other, like you mentioned) should be retained. We don't have to be kind or love our neighbor because superstitious people thought they were important. Educated people today can tell us they're important. God is not needed for there to be morality or ethics.
Unbelievable claims like rotted corpses reanimating, or supernatural beings visiting us, or all-powerful creators of the universe that expect us to sacrifice some doves and lambs when we sin, etc. should be rejected until experimental and theoretical backing occurs.
If one large religion, Christianity, can be shown to have been so dramatically caught up in believing a big lie (that the Jesus described in the NT really existed), then all similar faith-based systems (other religions) should be suspect. Their claims to reencarnation and multiply-armed gods should be rejected by rational people until experimental and theoretical support is forthcoming.
One could use big lies taught by smaller religions like the Mormons, or Jehovah's Witnesses, or Branch Davidians, but that would not be as effective, I think, as demonstrating the lie of Jesus of Nazareth.