[B]ecause there are no accounts of Jesus’ life from inside Jesus’ lifetime, we have credible evidence that Jesus did not exist.
If this were my argument, it would indeed be a straw man easily knocked down.
However, this is not my argument.
The absence of writings that reasonably should be there in the early first century is only one piece of data in the entire picture. This piece of data is of course consistent with a fictional Jesus who was invented later, but it does not alone make the case for a fictional Christ. I do not believe I have stated that it does make the case alone.
A synopsis of five major points in the case would be these:
1. No accounts of Jesus from the time, despite the noteworthy actions attributed to him in the "biographies" that appeared later
PLUS
2. Christianity appears to have begun without a human/historical Jesus as part of the religion; it was a "savior cult" similar to other religions of the time
PLUS
3. The first "biography" of Jesus appears on the scene very late and in the most suspicious way--in material that could easily be allegory, written and circulated by fervent believers within a young cult
PLUS
4. New pieces of the biography are "remembered" over time (i.e., as of 70 CE Jesus still has not been born)
PLUS
5. These pieces of "biography" that trickle in over time just so happen to fit the Hero Pattern, and have parallels in the Old Testament as well as the stories of competing savior gods who were popular at the time
Even though these five points do not represent the entire argument, together they are nonetheless a very strong case for a mythical Christ, if viewed without the distorting filter of religious faith. So I suppose I can understand why those who argue against the case tend to extract one single element and argue against that single element as if it contains the entire case.
But I am unaware of any proponent of the Christ Myth view who has stated that one single element (especially #1 above) makes the entire case on its own.
With regard to Socrates, I think you make the case for a real Socrates over a real Jesus quite well in your question: From Plato, we have a detailed written account of Socrates from someone who actually knew him. There is nothing even approaching this kind of evidence in Christian literature.
This is centuri0n, aka Frank Turk, who has been an internet apologist for about 10 years and has never really gained anything for himself through it but a handful of friends and a lot of ill-will. Most people, honestly, do not like to argue with him because he doesn't know how to let it go. He's a blogger of some minor note, and he's a "calvinist".
