As to CSflim's pet llama, there is an intrinsic difference, that being that God is not inherently self contradictory... examine again the adjectives you apply to your domesticated dromedary. But I'm just being picky.
As to God being used to explain away the inexplicable until we come up with the REAL explanation... you're presupposing your conclusion. You use the 'fact' that God isn't the reason for things to show that he isn't the reason for these things. You assume there is another explanation. I'll admit it's a little unfair to say this without specific cases to discuss, but then so's shrugging off God as a merely how people explain things away.
To the main topic...
Here's a look at the textual criticism of the Bible... I've seen it presented better, but this is what I've found so far while searching for this thread.
http://www.ici.edu/gql/reliable.html
Essentially, we know about Jesus with more certainty than we do about Julius Caesar.