You sense a deception here? The NIV folks think the four gospels were written some where within 50 to 70 AD. yet they don't see it as a reason to doubt their accuracy. All of the gospels seem to be pretty straight forward about being written after the fact.
As for the works of Josephus, I have not read them. It was just the result of a quick google search to give you a specific non-biblical source.
As for the political spin of the authors of the gospels, they seem to have done pretty well at winning converts in a hostile situation. Those guys must have been brilliant. Its a miracle that the religion they invented was so successful...no wait a minute, not a miracle...just a really good job of spinning. Yeah thats the ticket.
I don't have a specific problem with the Gospels being written after the fact, but that makes them memoirs and not historical records. I simply don't understand why someone that had such a huge impact on both the Jewish community and the Roman government would not have been cited at all in either groups extensive records of the day.
And no hard feelings about the Josephus thing; I was for the most part expecting you to cite it. It's pretty much the only non-biblical reference to Christ, and as such it has undergone some pretty intense scrutiny over the years. Its exposed flaws are pretty well known, as you've no doubt begun to realize.
I do find the success of the early Christian evangelists to be a testament to not only their tenacity but also their charismatic people skills. I'm not ready to automatically equate those attributes to evidence that God guided them though.